Activatable clostridial toxins

ABSTRACT

Compositions comprising activatable recombinant neurotoxins and polypeptides derived therefrom. The invention also comprises nucleic acids encoding such polypeptides, and methods of making such polypeptides and nucleic acids.

This application is a continuation and claims priority pursuant to 35 U.S.C. § 120 to U.S. patent application Ser. No. 11/832,108, filed Aug. 1, 2007, a continuation that claims priority pursuant to 35 U.S.C. § 120 to U.S. patent application Ser. No. 11/829,475, filed Jul. 27, 2007, a continuation-in-part application that claims priority pursuant to 35 U.S.C. § 120 to U.S. patent application Ser. No. 11/326,265, filed Jan. 5, 2006, a divisional application that claims priority pursuant to 35 U.S.C. § 120 to U.S. patent application Ser. No. 09/648,692, filed Aug. 8, 2000, an application that claims priority pursuant to pursuant to 35 U.S.C. § 119(e) to U.S. Provisional Patent Application Ser. No. 60/150,710 filed on Aug. 5, 1999 and claims priority pursuant to 35 U.S.C. § 120 to U.S. patent application Ser. No. 11/776,075 filed on Jul. 11, 2007, an application that claims priority pursuant to 35 U.S.C. § 119(e) to U.S. Provisional Patent Application Ser. No. 60/807,059 filed Jul. 11, 2006, each of which is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

This invention concerns methods and compositions useful in the fields of neurobiology, molecular biology, and medicine, as well as methods for the production of potentially toxic therapeutic agents and derivatives thereof. The invention also concerns recombinant clostridial neurotoxins (particular botulinum neurotoxins), modified versions thereof, and methods of making such molecules, for use as therapeutic agents, transporter molecules, adducts, and the like.

BACKGROUND OF THE INVENTION

Neurotoxins, such as those obtained from Clostridium botulinum and Clostridium tetani, are highly potent and specific poisons of neural cells, and other cells when delivered within such cells for therapeutic purposes. These Gram positive bacteria express two related but distinct toxins types, each comprising two disulfide-linked amino acid chains: a light chain (L) of about 50 KDa and a heavy chain (H) of about 100 KDa, which are wholly responsible for the symptoms of these diseases. The holotoxin is synthesised in vivo as a single-chain, then nicked in a post-translational modification to form the active neurotoxin comprising the separate L and H chains.

The tetanus and botulinum toxins are among the most lethal substances known to man, having a lethal dose in humans of between 0.1 ng and 1 ng per kilogram of body weight. Tonello et al., Adv. Exp. Med. & Biol. 389:251-260 (1996). Both toxins function by inhibiting neurotransmitter release in affected neurons. The tetanus neurotoxin (TeNT) acts mainly in the central nervous system, while botulinum neurotoxin (BoNT) acts at the neuromuscular junction and other cholinergic synapses in the peripheral nervous system; both act by inhibiting neurotransmitter release from the axon of the affected neuron into the synapse, resulting in paralysis.

The tetanus neurotoxin (TeNT) is known to exist in one immunologically distinct type; the botulinum neurotoxins (BoNT) are known to occur in seven different immunogenic types, termed BoNT/A through BoNT/G. While all of these types are produced by isolates of C. botulinum, two other species, C. baratii and C. butyricum also produce toxins similar to /F and /E, respectively. See e.g., Coffield et al., The Site and Mechanism of Action of Botulinum Neurotoxin in Therapy with Botulinum Toxin 3-13 (Jankovic J. & Hallett M. eds. 1994), the disclosure of which is incorporated herein by reference.

Regardless of type, the molecular mechanism of intoxication appears to be similar. In the first step of the process, the toxin binds to the presynaptic membrane of the target neuron through a specific interaction between the heavy (H) chain and a cell surface receptor; the receptor is thought to be different for each type of botulinum toxin and for TeNT. Dolly et al., Seminars in Neuroscience 6:149-158 (1994), incorporated by reference herein. The carboxyl terminus of the heavy chain appears to be important for targeting of the toxin to the cell surface. Id.

In the second step, the toxin crosses the plasma membrane of the poisoned cell. The toxin is first engulfed by the cell through receptor-mediated endocytosis, and an endosome containing the toxin is formed. The toxin then escapes the endosome into the cytoplasm of the cell. This last step is thought to be mediated by the amino terminus of the H chain, which triggers a conformational change of the toxin in response to a pH of about 5.5 or lower. Endosomes are known to possess a proton pump which decreases intra endosomal pH. The conformational shift exposes hydrophobic residues in the toxin, which permits the toxin to embed itself in the endosomal membrane. The toxin then translocates through the endosomal membrane into the cytosol.

The last step of the mechanism of botulinum toxin activity appears to involve reduction of the disulfide bond joining the H and light (L) chain. The entire toxic activity of botulinum and tetanus toxins is contained in the L chain of the holotoxin; the L chain is a zinc (Zn⁺⁺) endopeptidase which selectively cleaves proteins essential for recognition and docking of neurotransmitter-containing vesicles with the cytoplasmic surface of the plasma membrane, and fusion of the vesicles with the plasma membrane. TxNT, BoNT/B BoNT/D, BoNT/F, and BoNT/G cause degradation of synaptobrevin, also called vesicle-associated membrane protein (VAMP), a synaptosomal membrane protein. Most of the cytosolic domain of VAMP extending from the surface of the synaptic vesicle is removed as a result of any one of these cleavage events. Each toxin (except TeNT and BoNT/B) specifically cleaves a different bond.

BoNT/A and /E selectively cleave the plasma membrane-associated protein SNAP-25; this protein, which is also cleaved by BoNT/C1 (Foran et al., Biochem. 35:2630-2636 (1996)), is predominantly bound to and present on the cytosolic surface of the plasma membrane. BoNT/C cleaves syntaxin, an integral protein having most of its mass exposed to the cytosol. Syntaxin interacts with the calcium channels at presynaptic terminal active zones. See Tonello et al., Tetanus and Botulinum Neurotoxins in Intracellular Protein Catabolism 251-260 (Suzuki K. & Bond J. eds. 1996), the disclosure of which is incorporated by reference as part of this specification.

Both TeNT and BoNT are taken up at the neuromuscular junction. BoNT remains within peripheral neurons, and blocks release of the neurotransmitter acetylcholine from these cells. Through its receptor, TeNT enters vesicles that move in a retrograde manner along the axon to the soma, and is discharged into the intersynaptic space between motor neurons and the inhibitory neurons of the spinal cord. At this point, TeNT binds receptors of the inhibitory neurons, is again internalized, and the light chain enters the cytosol to block the release of the inhibitory neurotransmitters 4-aminobutyric acid (GABA) and glycine from these cells.

Because of its specifically localized effects, minute doses of BoNT have been used since 1981 as therapeutic agents in the treatment of patients suffering from dystonias, including strabismus (misalignment of the eye), bephlarospasm (involuntary eyelid closure) and hemifacial spasm. See e.g., Borodic et al, Pharmacology and Histology of the Therapeutic Application of Botulinum Toxin in Therapy with Botulinum Toxin 119-157 (Jankovic J. & Hallett eds. 1994), hereby incorporated by reference herein. Of the seven toxin types, BoNT/A is the most potent of the BoNTs, and the best characterized. Intramuscular injection of spastic tissue with small quantities of BoNT/A has also been used effectively to treat spasticity due to brain injury, spinal cord injury, stroke, multiple sclerosis and cerebral palsy. The extent of paralysis depends on both the dose and volume delivered to the target site.

Although the L chain is the moiety responsible for neural intoxication, it must be delivered to the neural cytoplasm in order to be toxic. Similarly, the single-chain holotoxin pro-forms exhibit relatively low toxicity until they are cleaved at one or more peptide bonds in an exposed loop region between their H and L chains to create the fully-active mature neurotoxins. As implied in the mechanism provided above, the H chain of each neurotoxin is essential for cell receptor binding and endocytosis, while both the L and the H chains (and an intact disulfide bond) are required for translocation of the toxin into the cytoplasm. As indicated above, the L chain alone is responsible for the toxicity caused by inhibition of acetylcholine secretion.

Despite the clear therapeutic efficacy of clostridial neurotoxin preparations, industrial production of the toxin is difficult. Production of neurotoxin from anaerobic Clostridium cultures is a cumbersome and time-consuming process including a multi-step purification protocol involving several protein precipitation steps and either prolonged and repeated crystallisation of the toxin or several stages of column chromatography. Significantly, the high toxicity of the product dictates that the procedure must be performed under strict containment (BL-3). During the fermentation process, the folded single-chain neurotoxins are activated by endogenous clostridial proteases through a process termed nicking. This involves the removal of approximately 10 amino acid residues from the single-chain to create the di-chain form in which the two chains remain covalently linked through the interchain disulfide bond.

The nicked neurotoxin is much more active than the unnicked form. The amount and precise location of nicking varies with the serotypes of the bacteria producing the toxin. The differences in single-chain neurotoxin activation and, hence, the yield of nicked toxin, are due to variations in the type and amounts of proteolytic activity produced by a given strain. For example, greater than 99% of C. botulinum type A single-chain neurotoxin is activated by the Hall A C. botulinum strain, whereas type B and E strains produce toxins with lower amounts of activation (0 to 75% depending upon the fermentation time). Thus, the high toxicity of the mature neurotoxin plays a major part in the commercial manufacture of neurotoxins as therapeutic agents.

The degree of activation of engineered clostridial toxins is, therefore, an important consideration for manufacture of these materials. It would be a major advantage if neurotoxins such as BoNT and TeNT could be expressed in high yield in rapidly-growing bacteria (such as heterologous E. coli cells) as relatively non-toxic single-chains (or single-chains having reduced toxic activity) which are safe, easy to isolate and simple to convert to the fully-active form.

With safety being a prime concern, previous work has concentrated on the expression in E. coli and purification of individual H and L chains of TeNT and BoNT; these isolated chains are, by themselves, non-toxic; see Li et al., Biochemistry 33:7014-7020 (1994); Zhou et al., Biochemistry 34:15175-15181 (1995), hereby incorporated by reference herein. Following the separate production of these peptide chains and under strictly controlled conditions the H and L subunits can be combined by oxidative disulphide linkage to form the neuroparalytic di-chains. Unfortunately, this strategy has several drawbacks.

Firstly, it is not practical to express and isolate large amounts of the individual chains; in particular, in the absence of the L chain the isolated H chain is quite insoluble in aqueous solution and is highly susceptible to proteolytic degradation. Secondly, the in vitro oxidation of the individually expressed and purified H and L chains to produce the active di-chain is very inefficient, and leads to low yields of active toxin and the production of many inactive incorrectly folded or oxidized forms. The purification of the correctly folded and oxidized H and L chain-containing toxin is difficult, as is its separation from these inactive forms and the unreacted separate H and L chains.

It would therefore be useful and advantageous to express clostridial neurotoxins as inactive (or less active) single-chain forms, to eliminate the need for the time-consuming and inefficient reconstitution of the constituent chains, to maintain solubility of the protein chains, to reduce protein misfolding and consequent susceptibility to protease attack, to improve toxin yield, and/or to provide a simple method for the purification of the toxin.

Additionally, it would be useful to engineer these toxins to provide single-chain, modified neurotoxin molecules having novel therapeutic properties and/or longer duration of action, or toxic or non-toxic forms for use as transport molecules capable of delivering a therapeutic moiety to nerve or other cell types. By expressing such proteins as a single-chain, the yield and purification of the engineered proteins would be vastly improved.

SUMMARY OF THE INVENTION

The present invention is directed to recombinant and isolated proteins comprising a functional binding domain, translocation domain, and therapeutic domain in which such proteins also include an amino acid sequence that is susceptible to specific cleavage in vitro following expression as a single-chain. Such proteins may include clostridial neurotoxins and derivatives thereof, such as those proteins disclosed in Dolly et al., Modified Clostridial Toxins for Use as Transport Proteins, International Patent Publication WO 95/32738 (Dec. 7, 1995); and Foster et al., Clostridial Toxin Derivatives Able to Modify Peripheral Sensory Afferent Functions, U.S. Pat. No. 5,989,545 (Nov. 23, 1999), both incorporated by reference herein.

In one embodiment of the invention the protein comprises the functional domains of a clostridial neurotoxin H chain and some or all of the functions of a clostridial neurotoxin L chain in a single polypeptide chain, and having an inserted proteolytic cleavage site located between the H domain and the L domain by which the single-chain protein may be cleaved to produce the individual chains, preferably covalently linked by a disulfide linkage. The invention also includes methods of making such proteins and expressing them within a cell, as well as nucleic acid vectors for the transfer and expression of the nucleotide sequence regions encoding such proteins and cells containing such vectors. The proteolytic cleavage sites comprise amino acid sequences that are selectively recognized and cleaved by a specific enzyme.

In a preferred aspect of the invention, the expressed single-chain proteins comprise the biologically active domains of the H chain and L chain of a clostridial neurotoxin. Scission at the internal proteolytic cleavage site separating the chain domains thus results in the activation of a neurotoxin having full activity.

In another aspect of the invention the single-chain proteins comprise a binding domain targeted to a cell receptor other than one borne by a motor neuron. Such a binding domain may specific bind to, for example, a sensory afferent neuron, or to a non-neuronal cell type or tissue, such as pancreatic acinar cells. The single-chain proteins will contain a translocation domain similar to that of clostridial neurotoxins, and a therapeutic moiety. The therapeutic moiety may be a clostridial neurotoxin light chain, or may be a different therapeutic moiety such as an enzyme, a transcribable nucleotide sequence, growth factor, an antisense nucleotide sequence and the like.

Preferably, the toxins and toxin-based proteins of the present invention will be tailored to contain an additional amino acid sequence comprising a binding tag able to bind a target compound at sufficiently high efficiency to facilitate rapid isolation of the toxin protein. Proteins containing such binding sites are many and well known to those of skill in the art, and may comprise, without limitation, monoclonal antibodies, maltose binding protein, glutathione-S-transferase, protein A, a His₆ tag, and the like.

Because such proteins exhibit binding selectivity to a certain compound or compound type, the target compound may be immobilized to a solid support, including without limitation, a chromotography resin or microtiter well and used for affinity purification of the modified toxin. The toxin molecule can then be eluted by standard methods, such as through the use of a high salt solution or specific antagonist.

To minimize the safety risk associated with handling neurotoxin, the toxins of the this aspect of the present invention are expressed as their low activity (or inactive) single-chain proforms, then, by a carefully controlled proteolytic reaction in vitro, they are activated, preferably to the same potency level as the native neurotoxin from which they were derived. To improve the efficiency and rate of proteolytic cleavage the engineered proteolytic cleavage sites can be designed to occur in a specially-designed loop between the H and L portions of the single amino acid chain that promotes accessibility of the protease to the holotoxin substrate.

To reduce the risk of unintentional activation of the toxin by human or commonly encountered proteases, the amino acid sequences of the cleavage site are preferably designed to have a high degree of specificity to proteolytic enzymes which do not normally occur in humans (as either human proteases or occurring in part of the foreseeable human fauna and flora). A non-exclusive list of examples of such proteases includes a protease isolated or derived from a non-human Enterokinase, like bovine enterokinase, a protease isolated or derived from plant legumain, a protease isolated or derived from plant papain, such as, e.g., like from Carica papaya, a protease isolated or derived from insect papain, like from the silkworm Sitophilus zeamatus, a protease isolated or derived from crustacian papain, a protease isolated or derived from Tobacco etch virus (TEV), a protease isolated or derived from a Tobacco Vein Mottling Virus (TVMV), a protease isolated or derived from Bacillus amyliquifaciens, such as, e.g., subtilisin and GENENASE®, a protease isolated or derived from 3c protease from human rhinovirus (HRV), such as, e.g., PRESCISSION®, a protease isolated or derived from 3c protease from human enteroviruses (HEV), and a protease isolated or derived from a non-human Caspase 3.

In an aspect of the invention the single-chain polypeptide is an isolated polypeptide. By “isolated” is meant removed from its natural environment. For example, for a protein expressed within the cell, isolation includes preparation of a cell lysate as well as subsequent purification steps. A protein expressed extracellularly may be isolated by, for example, separation of the supernatant from the cells as well as any subsequent purification steps.

In another aspect of the invention the interchain loop region of the C. botulinum subtype E neurotoxin, which is normally resistant to proteolytic nicking in the bacterium and mammals, is modified to include the inserted proteolytic cleavage site, and this loop region used as the interchain loop region in the single-chain toxin or modified toxin molecules of the present invention. It is believed that using the loop from C. botulinum subtype E will stabilize the unnicked toxin molecule in vivo, making it resistant to undesired cleavage until activated through the use of the selected protease.

In yet another aspect of the invention compositions are contemplated comprising recombinant forms of BoNT/E expressed as a single-chain polypeptide.

In still another aspect contemplate recombinant chimeric and/or modified toxin derivatives expressed as a single-chain polypeptide. Such polypeptide may be molecular transporters, such as, without limitation, those disclosed in Dolly et al., European Patent Specification EP 0 760 681 B1, incorporated by reference herein.

In a further aspect the invention includes neurotoxin derivatives comprising at least a portion of a light chain from one clostridial neurotoxin or subtype thereof, and at least a portion of a heavy chain from another neurotoxin or neurotoxin subtype, as well as methods for their production. In one embodiment the hybrid neurotoxin may contain the entire light chain of a light chain from one neurotoxin subtype and the heavy chain from another neurotoxin subtype. In another embodiment, a chimeric neurotoxin derivative may contain a portion (e.g., the binding domain) of the heavy chain of one neurotoxin subtype, with another portion of the heavy chain being from another neurotoxin subtype. Similarly or alternatively, the therapeutic element may comprise light chain portions from different neurotoxins.

Such hybrid or chimeric neurotoxin derivatives are useful, for example, as a means of delivering the therapeutic benefits of such neurotoxins to patients who are immunologically resistant to a given neurotoxin subtype, to patients who may have a lower than average concentration of receptors to a given neurotoxin heavy chain binding moiety, or to patients who may have a protease-resistant variant of the membrane or vesicle toxin substrate (e.g., SNAP-25, VAMP and syntaxin). Creation of recombinant chimeric or hybrid neurotoxin derivatives having a light chain with different substrate would permit such patients to respond to neurotoxin therapy.

With regard to immunological resistance, it is known that most neurotoxin epitopes exist on the heavy chain portion of the toxin. Thus if a patient has neutralizing antibodies to, for example BoNT/A, a chimeric neurotoxin containing the heavy chain from BoNT/E and the light chain from BoNT/A (which has a longer duration of therapeutic activity than other neurotoxin light chains) would overcome this resistance. Likewise if the patient has few cell surface receptors for BoNT/A, the chance are great that the same patient would have adequate receptors to another BoNT subtype. By creating a hybrid or chimeric neurotoxin (such as one containing at least a portion of a heavy chain selected from the group consisting of HC_(A), HC_(B), HC_(C1), HC_(D), HC_(E), HC_(F), and HC_(G) and a at least a portion of a light chain selected from a different clostridial neurotoxin subtype, said light chain being selected from the group consisting of LC_(A), LC_(B), LC_(C1), LC_(D), LC_(E), LC_(F), and LC_(G)) combining the heavy chain of that subtype with the most therapeutically appropriate light chain (for example, the BoNT/A light chain) the patient could better respond to neurotoxin therapy.

Another advantage of the hybrid or chimeric neurotoxin derivatives described above is related to the fact that certain of the light chains (e.g., LC_(A)) have a long duration of action, others having a short duration of action (e.g., LC_(E) and LC_(F)) while still others have an intermediate duration of activity (e.g., LC_(B)). Thus, hybrid and chimeric neurotoxins represent second and third generation neurotoxin drugs in which the neurotoxin activity may be tailored to a specific therapeutic need or condition, with different drugs having different activities, substrate specificities or duration of activity.

Such hybrid or chimeric neurotoxins would also be useful in treating a patient (such as a soldier or laboratory worker) who has been inoculated with the pentavalent BoNT vaccine. Such vaccines do not contain BoNT/F; thus, combining the appropriate light chain with the BoNT/F heavy chain would create a therapeutic agent which is effective in such a patient where current therapeutic neurotoxins may not be.

The same strategy may be useful in using derivatives of clostridial neurotoxins with a therapeutic moiety other than an active neurotoxin light chain. As the heavy chain of such an agent would be derived from a neurotoxin, it may be advantageous to use a lesser known, or rarer heavy chain to avoid resistance mechanisms neutralizing the effectiveness of the therapeutic neurotoxin derivative.

By the same token, the binding moiety may be one other than a binding moiety derived from a clostridial neurotoxin heavy chain, thus providing a targeting function to cell types other than motor neurons.

Also included herein are methods for the construction, expression, and purification of such molecules in high yield as biologically active entities.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a diagrammatic view of the single-chain TeNT construct in plasmid pTrcHisA and the nucleotide sequence of the junction region.

FIG. 1B shows the and amino acid sequence connecting the carboxyl terminus of the L chain and the amino terminus of the H chain and an engineered loop region containing an enterokinase cleavage site.

FIG. 2A is a representation of a Western blot of an SDS-PAGE gel of cell extracts of E. coli JM 109 transformants containing 2 different recombinant single-chain toxins, either before or after induction of plasmid protein expression with IPTG. The antibody used for detection is an anti-His₆ monoclonal antibody.

FIG. 2B is a Western blot of IPTG-induced cell extracts from cells transformed with the E234A construct.

FIG. 3A shows the results of an experiment in which affinity purified recombinant single-chain (SC) TeNT is nicked with enterokinase, then separated using SDS-PAGE and visualized using Commassie Brilliant Blue under reducing and non-reducing conditions.

FIG. 3B shows the results of an experiment in which affinity purified recombinant single-chain (SC) TeNT is nicked with enterokinase, then separated using SDS-PAGE under reducing and non-reducing conditions and subjected to a Western blot using anti TeNT heavy chain antibody.

FIG. 4 is a plot of the degree of paralysis induced in a nerve/muscle preparation in vitro using native TeNT, and recombinant single-chain neurotoxin before, and after nicking as a function of time.

FIG. 5 is a depiction of the peptide fragments generated upon incubation of the recombinant single-chain TeNT with trypsin and Arg C protease, and deduction, from the N-terminal sequences of one of the resulting fragments, of the amino acid sequence recognized by these agents.

FIG. 6 shows the digestion of unnicked SC WT TeNT and SC R496G TeNT with various concentrations of trypsin.

FIG. 7 shows the inhibitory effect upon TeNT stimulated inhibition of Ca⁺⁺-dependent neurotransmitter release of preincubating cerebellar cells with the E234A mutant TeNT.

FIG. 8 shows the effect upon Ca⁺⁺-dependent neurotransmitter release of cerebellar neurons upon exposure to native, recombinant E234A mutant single-chain, and the recombinant R496G mutant single-chain TeNT.

FIG. 9 shows the inhibitory effect upon TeNT-stimulated paralytic activity of preincubating mouse hemi diaphrams with the E234A mutant TeNT.

FIG. 10 shows the scheme for construction of a plasmid encoding single-chain BoNT/E, and an agarose gel electrophoretogram of the PCR fragment obtained during the construction of the plasmid.

FIG. 11 shows the scheme for construction of a plasmid encoding the E212Q proteolytically inactive single-chain BoNT/E mutant, and an agarose gel electrophoretogram of the inverse PCR fragment obtained during the construction of the plasmid.

FIG. 12 shows the expression and purification scheme for recombinant single-chain BoNT/E, and a SDS-PAGE electrophoretogram and Western blot of the purification fractions.

FIG. 13 shows SDS-PAGE electrophoretograms under reducing and non-reducing conditions of native recombinant unnicked, and recombinant nicked BoNT/E, and Western Blots directed towards the heavy and light chains of the toxin.

FIG. 14 shows the results of incubating native BoNT/E, recombinant nicked and un-nicked BoNT/E, and the E212Q mutant with a GST-SNAP-25[140-205] protease substrate.

FIG. 15 shows the effect upon Ca⁺⁺-dependent glutamate release of incubating cerebellar cells with native BoNT/E, un-nicked recombinant single-chain BoNT/E, and nicked recombinant single-chain BoNT/E.

FIG. 16A shows the effects on muscle tension of incubating mouse phrenic-nerve hemi-diaphragms with 0.2 nM recombinant nicked BoNT/E (◯) or 0.2 nM native BoNT/E (□).

FIG. 16B shows the effects on muscle tension of incubating mouse phrenic-nerve hemi-diaphragms with 1 nM recombinant un-nicked (◯), 1 nM recombinant nicked () or 0.05 nM recombinant nicked (∇) BoNT/E.

FIG. 17 shows the attenuation of paralytic activity on mouse phrenic-nerve hemi-diaphragms of preincubation with the inactive E212Q mutant prior to exposure to native nicked BoNT/E toxin.

FIG. 18 shows a schematic of the current paradigm of neurotransmitter release and Clostridial toxin intoxication in a central and peripheral neuron. FIG. 18A shows a schematic for the neurotransmitter release mechanism of a central and peripheral neuron. The release process can be described as comprising two steps: 1) vesicle docking, where the vesicle-bound SNARE protein of a vesicle containing neurotransmitter molecules associates with the membrane-bound SNARE proteins located at the plasma membrane; and 2) neurotransmitter release, where the vesicle fuses with the plasma membrane and the neurotransmitter molecules are exocytosed. FIG. 18B shows a schematic of the intoxication mechanism for tetanus and botulinum toxin activity in a central and peripheral neuron. This intoxication process can be described as comprising four steps: 1) receptor binding, where a Clostridial toxin binds to a Clostridial receptor system and initiates the intoxication process; 2) complex internalization, where after toxin binding, a vesicle containing the toxin/receptor system complex is endocytosed into the cell; 3) light chain translocation, where multiple events are thought to occur, including, e.g., changes in the internal pH of the vesicle, formation of a channel pore comprising the HN domain of the Clostridial toxin heavy chain, separation of the Clostridial toxin light chain from the heavy chain, and release of the active light chain and 4) enzymatic target modification, where the activate light chain of Clostridial toxin proteolytically cleaves its target SNARE substrate, such as, e.g., SNAP-25, VAMP or Syntaxin, thereby preventing vesicle docking and neurotransmitter release.

FIG. 19 shows the domain organization of naturally-occurring Clostridial toxins. The single-chain form depicts the amino to carboxyl linear organization comprising an enzymatic domain, a translocation domain, and a binding domain. The di-chain loop region located between the translocation and enzymatic domains is depicted by the double SS bracket. This region comprises an endogenous di-chain loop protease cleavage site that upon proteolytic cleavage with a naturally-occurring protease, such as, e.g., an endogenous Clostridial toxin protease or a naturally-occurring protease produced in the environment, converts the single-chain form of the toxin into the di-chain form. Above the single-chain form, the H_(CC) region of the Clostridial toxin binding domain is depicted. This region comprises the β-trefoil domain which comprises in a amino to carboxyl linear organization an α-fold, a β4/β5 hairpin turn, β-fold, a β8/β9 hairpin turn and a γ-fold.

FIG. 20 shows modified Clostridial toxins with an enhanced targeting domain located at the amino terminus of the modified toxin. FIG. 20A depicts the single-chain polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising a binding element, a translocation element, a di-chain loop region comprising an exogenous protease cleavage site (P), and a therapeutic element. Upon proteolytic cleavage with a P protease, the single-chain form of the toxin is converted to the di-chain form. FIG. 20B depicts the single polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising a binding element, a therapeutic element, a di-chain loop region comprising an exogenous protease cleavage site (P), and a translocation element. Upon proteolytic cleavage with a P protease, the single-chain form of the toxin is converted to the di-chain form.

FIG. 21 shows modified Clostridial toxins with an enhanced targeting domain located between the other two domains. FIG. 21A depicts the single polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising a therapeutic element, a di-chain loop region comprising an exogenous protease cleavage site (P), a binding element, and a translocation element. Upon proteolytic cleavage with a P protease, the single-chain form of the toxin is converted to the di-chain form. FIG. 21B depicts the single polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising a translocation element, a di-chain loop region comprising an exogenous protease cleavage site (P), a binding element, and a therapeutic element. Upon proteolytic cleavage with a P protease, the single-chain form of the toxin is converted to the di-chain form. FIG. 21C depicts the single polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising a therapeutic element, a binding element, a di-chain loop region comprising an exogenous protease cleavage site (P), and a translocation element. Upon proteolytic cleavage with a P protease, the single-chain form of the toxin is converted to the di-chain form. FIG. 21D depicts the single polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising a translocation element, a binding element, a di-chain loop region comprising an exogenous protease cleavage site (P), and a therapeutic element. Upon proteolytic cleavage with a P protease, the single-chain form of the toxin is converted to the di-chain form.

FIG. 22 shows modified Clostridial toxins with an enhanced targeting domain located at the carboxyl terminus of the modified toxin. FIG. 22A depicts the single polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising a therapeutic element, a di-chain loop region comprising an exogenous protease cleavage site (P), a translocation element, and a binding element. Upon proteolytic cleavage with a P protease, the single-chain form of the toxin is converted to the di-chain form. FIG. 22B depicts the single polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising a translocation element, a di-chain loop region comprising an exogenous protease cleavage site (P), a therapeutic element, and a binding element. Upon proteolytic cleavage with a P protease, the single-chain form of the toxin is converted to the di-chain form.

DETAILED DESCRIPTION OF THE INVENTION

Clostridia toxins produced by Clostridium botulinum, Clostridium tetani, Clostridium baratii and Clostridium butyricum are the most widely used in therapeutic and cosmetic treatments of humans and other mammals. Strains of C. botulinum produce seven antigenically-distinct types of Botulinum toxins (BoNTs), which have been identified by investigating botulism outbreaks in man (BoNT/A, /B, /E and /F), animals (BoNT/C1 and /D), or isolated from soil (BoNT/G). BoNTs possess approximately 35% amino acid identity with each other and share the same functional domain organization and overall structural architecture. It is recognized by those of skill in the art that within each type of Clostridial toxin there can be subtypes that differ somewhat in their amino acid sequence, and also in the nucleic acids encoding these proteins. For example, there are presently four BoNT/A subtypes, BoNT/A1, BoNT/A2, BoNT/A3 and BoNT/A4, with specific subtypes showing approximately 89% amino acid identity when compared to another BoNT/A subtype. While all seven BoNT serotypes have similar structure and pharmacological properties, each also displays heterogeneous bacteriological characteristics. In contrast, tetanus toxin (TeNT) is produced by a uniform group of C. tetani. Two other species of Clostridia, C. baratii and C. butyricum, also produce toxins, BaNT and BuNT respectively, which are similar to BoNT/F and BoNT/E, respectively.

Each mature di-chain molecule comprises three functionally distinct domains: 1) an enzymatic domain located in the LC that includes a metalloprotease region containing a zinc-dependent endopeptidase activity which specifically targets core components of the neurotransmitter release apparatus; 2) a translocation domain contained within the amino-terminal half of the HC (H_(N)) that facilitates release of the LC from intracellular vesicles into the cytoplasm of the target cell; and 3) a binding domain found within the carboxyl-terminal half of the HC (H_(C)) that determines the binding activity and binding specificity of the toxin to the receptor complex located at the surface of the target cell. The H_(C) domain comprises two distinct structural features of roughly equal size that indicate function and are designated the H_(CN) and H_(CC) subdomains. Table 1 gives approximate boundary regions for each domain found in exemplary Clostridial toxins.

TABLE 1 Clostridial Toxin Reference Sequences and Regions Toxin SEQ ID NO: LC H_(N) H_(C) BoNT/A 1 M1-K448 A449-K871 N872-L1296 BoNT/B 2 M1-K441 A442-S858 E859-E1291 BoNT/C1 3 M1-K449 T450-N866 N867-E1291 BoNT/D 4 M1-R445 D446-N862 S863-E1276 BoNT/E 5 M1-R422 K423-K845 R846-K1252 BoNT/F 6 M1-K439 A440-K864 K865-E1274 BoNT/G 7 M1-K446 S447-S863 N864-E1297 TeNT 8 M1-A457 S458-V879 I880-D1315 BaNT 9 M1-K431 N432-I857 I858-E1268 BuNT 10 M1-R422 K423-I847 Y1086-K1251

The binding, translocation and enzymatic activity of these three functional domains are all necessary for toxicity. While all details of this process are not yet precisely known, the overall cellular intoxication mechanism whereby Clostridial toxins enter a neuron and inhibit neurotransmitter release is similar, regardless of serotype or subtype. Although the applicants have no wish to be limited by the following description, the intoxication mechanism can be described as comprising at least four steps: 1) receptor binding, 2) complex internalization, 3) light chain translocation, and 4) enzymatic target modification (see FIG. 18). The process is initiated when the H_(C) domain of a Clostridial toxin binds to a toxin-specific receptor system located on the plasma membrane surface of a target cell. The binding specificity of a receptor complex is thought to be achieved, in part, by specific combinations of gangliosides and protein receptors that appear to distinctly comprise each Clostridial toxin receptor complex. Once bound, the toxin/receptor complexes are internalized by endocytosis and the internalized vesicles are sorted to specific intracellular routes. The translocation step appears to be triggered by the acidification of the vesicle compartment. This process seems to initiate two important pH-dependent structural rearrangements that increase hydrophobicity and promote formation di-chain form of the toxin. Once activated, light chain endopeptidase of the toxin is released from the intracellular vesicle into the cytosol where it appears to specifically targets one of three known core components of the neurotransmitter release apparatus. These core proteins, vesicle-associated membrane protein (VAMP)/synaptobrevin, synaptosomal-associated protein of 25 kDa (SNAP-25) and Syntaxin, are necessary for synaptic vesicle docking and fusion at the nerve terminal and constitute members of the soluble N-ethylmaleimide-sensitive factor-attachment protein-receptor (SNARE) family. BoNT/A and BoNT/E cleave SNAP-25 in the carboxyl-terminal region, releasing a nine or twenty-six amino acid segment, respectively, and BoNT/C1 also cleaves SNAP-25 near the carboxyl-terminus. The botulinum serotypes BoNT/B, BoNT/D, BoNT/F and BoNT/G, and tetanus toxin, act on the conserved central portion of VAMP, and release the amino-terminal portion of VAMP into the cytosol. BoNT/C1 cleaves syntaxin at a single site near the cytosolic membrane surface. The selective proteolysis of synaptic SNAREs accounts for the block of neurotransmitter release caused by Clostridial toxins in vivo. The SNARE protein targets of Clostridial toxins are common to exocytosis in a variety of non-neuronal types; in these cells, as in neurons, light chain peptidase activity inhibits exocytosis, see, e.g., Yann Humeau et al., How Botulinum and Tetanus Neurotoxins Block Neurotransmitter Release, 82(5) Biochimie. 427-446 (2000); Kathryn Turton et al., Botulinum and Tetanus Neurotoxins: Structure, Function and Therapeutic Utility, 27(11) Trends Biochem. Sci. 552-558. (2002); Giovanna Lalli et al., The Journey of Tetanus and Botulinum Neurotoxins in Neurons, 11(9) Trends Microbiol. 431-437, (2003).

Clostridial toxins are each translated as a single-chain polypeptide of approximately 150 kDa that is subsequently cleaved by proteolytic scission within a disulfide loop by a naturally-occurring protease (FIG. 18). This cleavage occurs within the discrete di-chain loop region created between two cysteine residues that form a disulfide bridge. This posttranslational processing yields a di-chain molecule comprising an approximately 50 kDa light chain (LC) and an approximately 100 kDa heavy chain (HC) held together by the single disulfide bond and non-covalent interactions between the two chains. The naturally-occurring protease used to convert the single-chain molecule into the di-chain is currently not known. In some bacterial serotypes, such as, e.g., a BoNT/A, a BoNT/B proteolytic, a BoNT/F proteolytic, a BaNT proteolytic strain, or a TeNT, the naturally-occurring protease is produced endogenously by the bacteria serotype and cleavage occurs within the cell before the toxin is release into the environment. However, in other bacterial serotypes, such as, e.g., a BoNT/B nonproteolytic, a BoNT/C1, a BoNT/D, a BoNT/E, a BoNT/F nonproteolytic, a BoNT/G, a BaNT nonproteolytic, or a BuNT, the bacterial strain appears not to produce appreciable amounts of an endogenous protease capable of converting the single-chain form of the toxin into the di-chain form. In these situations, the toxin is released from the cell as a single-chain toxin which is subsequently converted into the di-chain form by a naturally-occurring protease found in the environment.

The compositions and methods of the present invention involve modified neurotoxins, their synthesis and use. Di-chain neurotoxins that are normally activated by scission of a single-chain polypeptide by indigenous proteases can be modified at the nucleic acid level by alteration or removal of the nucleotide sequence encoding the indigenous protease cleavage site and insertion of a nucleotide sequence encoding another different proteolytic cleavage site resistant to cleavage by host cell or human proteases. The inserted amino acid sequence is designed to be cleaved in vitro through the use of a cleaving agent chosen in advance of expression that is, absent from both human and host cell tissue.

The amino acid sequences recognized by many proteases, and their cleavage specificity are well-known to those of skill in the art. Thus, both the design of a specific proteolytic cleavage site in the loop region between the L and H chain portions of the single-chain toxin and the modification of incidental protease sites in the polypeptide to be protease-resistant is a routine matter of comparing the specificity and recognition sequences for various proteins. In the first case, the specificity of a candidate proteolytic site need not be totally exclusive, but merely needs to exclude cleavage sites for human and/or host cell proteases that might be present during the handling, storage and purification of the single-chain neurotoxin. Of course, it is preferable that the protease site is as specific as possible. In the latter case, the modification of the proteolytic cleavage site need only be sufficient to render the site resistant to the activator protease and to human and host cell proteases.

As mentioned above, a Clostridial toxin is converted from a single polypeptide form into a di-chain molecule by proteolytic cleavage. While the naturally-occurring protease is currently not known, cleavage occurs within the di-chain loop region between the two cysteine residues that form the disulfide bridge (Table 2). As used herein, the term “di-chain loop region” means the amino acid sequence of a Clostridial toxin containing a protease cleavage site used to convert the single-chain polypeptide form of a Clostridial toxin into the di-chain form. Non-limiting examples of a Clostridial toxin di-chain loop region, include, a di-chain loop region of BoNT/A comprising SEQ ID NO: 11; a di-chain loop region of BoNT/B comprising SEQ ID NO: 12; a di-chain loop region of BoNT/C1 comprising SEQ ID NO: 13; a di-chain loop region of BoNT/D comprising SEQ ID NO: 14; a di-chain loop region of BoNT/E comprising SEQ ID NO: 15; a di-chain loop region of BoNT/F comprising SEQ ID NO: 16; a di-chain loop region of BoNT/G comprising SEQ ID NO: 17; a di-chain loop region of TeNT comprising SEQ ID NO: 18, a di-chain loop region of BaNT comprising SEQ ID NO: 19, and a di-chain loop region of BuNT comprising SEQ ID NO: 20 (Table 2).

TABLE 2 Di-chain Loop Region of Clostridial Toxins SEQ ID Di-Chain Loop Region Including Toxin NO: a Di-Chain Protease Cleavage Site BoNT/A 11 CVRGIITSKTKSLDKGYNK*----ALNDLC BoNT/B 12 CKSVK*-------------------APGIC BoNT/C1 13 CHKAIDGRSLYNK*------------TLDC BoNT/D 14 CLRLTKNSR*---------------DDSTC BoNT/E 15 CKNIVSVKGIR*--------------KSIC BoNT/F 16 CKSVIPRKGTK*------------APPRLC BoNT/G 17 CKPVMYKNTGK*--------------SEQC TeNT 18 CKKIIPPTNIRENLYNRTA*SLTDLGGELC BaNT 19 CKSIVSKKGTK*--------------NSLC BuNT 20 CKNIVSVKGIR*--------------KSIC The amino acid sequence displayed are as follows: BoNT/A, residues 430-454 of SEQ ID NO: 1; BoNT/B, residues 437-446 of SEQ ID NO: 2; BoNT/C1, residues 437-453 of SEQ ID NO: 3; BoNT/D, residues 437-450 of SEQ ID NO: 4; BoNT/E, residues 412-426 of SEQ ID NO: 5; BoNT/F, residues 429-445 of SEQ ID NO: 6; BoNT/G, residues 436-450 of SEQ ID NO: 7; TeNT, residues 439-467 of SEQ ID NO: 8; BaNT, residues 421-435 of SEQ ID NO: 9; and BuNT, residues 412-426 of SEQ ID NO: 10. An asterisks (*) indicates the peptide bond of the P₁-P₁ cleavage site that is believed to be cleaved by a Clostridial toxin di-chain loop protease.

The inserted amino acid sequence may be chosen to confer susceptibility to a chemical agent capable of cleaving peptide bonds, such as cyanogen bromide. However, and much more preferably, the encoded amino acid sequence may comprise a proteolytic cleavage site highly specific for a selected protease. The selected protease may be any protease that recognizes a specific amino acid sequence and cleaves a peptide bond near or at that location, but the selected protease is very preferably not a human protease such as, e.g., human trypsin, chymotrypsin or pepsin, or a protease expressed in the host cell. Moreover, the selected protease does not recognize the same amino acid sequence as the endogenous protease (i.e., the naturally-occurring di-chain loop protease cleavage site). Finally, the selected protease should not be one expressed by the host cell that contains the plasmid encoding the recombinant neurotoxin. Any non-human protease recognizing a relatively rare amino acid sequence may be used, provided that the amino acid recognition sequence is also known. Examples of proteases to be selected as activators may include any of the following, without limitation: a protease isolated or derived from non-human Enterokinase, such as, e.g., a bovine enterokinase, a protease isolated or derived from plant legumain, a protease isolated or derived from plant papain, such as, e.g., like from Carica papaya, a protease isolated or derived from insect papain, like from the silkworm Sitophilus zeamatus, a protease isolated or derived from crustacian papain, a protease isolated or derived from Tobacco etch virus (TEV), a protease isolated or derived from a Tobacco Vein Mottling Virus (TVMV), a protease isolated or derived from Bacillus amyliquifaciens, such as, e.g., subtilisin and GENENASE®, a protease isolated or derived from 3c protease from human rhinovirus (HRV), such as, e.g., PRESCISSION®, a protease isolated or derived from 3c protease from human enteroviruses (HEV) and a protease isolated or derived from a non-human Caspase 3, such as, e.g., a mouse Caspase 3.

In another aspect of the invention, a modified Clostridial toxin comprises, in part, an exogenous protease cleavage site within a di-chain loop region. As used herein, the term “exogenous protease cleavage site” is synonymous with a “non-naturally occurring protease cleavage site” or “non-native protease cleavage site” and means a protease cleavage site that is not normally present in a di-chain loop region from a naturally occurring Clostridial toxin, with the proviso that the exogenous protease cleavage site is not a human protease cleavage site or a protease cleavage site that is susceptible to a protease being expressed in the host cell that is expressing a construct encoding an activatable polypeptide disclosed in the present specification. It is envisioned that any and all exogenous protease cleavage sites can be used to convert the single-chain polypeptide form of a Clostridial toxin into the di-chain form are useful to practice aspects of the present invention. Non-limiting examples of exogenous protease cleavage sites include, e.g., a plant papain cleavage site, an insect papain cleavage site, a crustacian papain cleavage site, a non-human enterokinase cleavage site, a human rhinovirus 3C protease cleavage site, human enterovirus 3C protease cleavage site, a tobacco etch virus (TEV) protease cleavage site, a Tobacco Vein Mottling Virus (TVMV) cleavage site, a subtilisin cleavage site, a hydroxylamine cleavage site, or a non-human Caspase 3 cleavage site.

It is envisioned that an exogenous protease cleavage site of any and all lengths can be useful in aspects of the present invention with the proviso that the exogenous protease cleavage site is capable of being cleaved by its respective protease. Thus, in aspects of this embodiment, an exogenous protease cleavage site can be, e.g., at least 6 amino acids in length, at least 7 amino acids in length, at least 8 amino acids in length, at least 9 amino acids in length, at least 10 amino acids in length, at least 15 amino acids in length, at least 20 amino acids in length, at least 25 amino acids in length, at least 30 amino acids in length, at least 40 amino acids in length, at least 50 amino acids in length or at least 60 amino acids in length. In other aspects of this embodiment, an exogenous protease cleavage site can be, e.g., at most 6 amino acids in length, at most 7 amino acids in length, at most 8 amino acids in length, at most 9 amino acids in length, at most 10 amino acids in length, at most 15 amino acids in length, at most 20 amino acids in length, at most 25 amino acids in length, at most 30 amino acids in length, at most 40 amino acids in length, at most 50 amino acids in length or at most 60 amino acids in length.

In an embodiment, an exogenous protease cleavage site is located within the di-chain loop of a modified Clostridial toxin. In aspects of this embodiment, a modified Clostridial toxin comprises an exogenous protease cleavage site comprises, e.g., a plant papain cleavage site, an insect papain cleavage site, a crustacian papain cleavage site, a non-human enterokinase protease cleavage site, a Tobacco Etch Virus protease cleavage site, a Tobacco Vein Mottling Virus protease cleavage site, a human rhinovirus 3C protease cleavage site, a human enterovirus 3C protease cleavage site, a subtilisin cleavage site, a hydroxylamine cleavage site, a SUMO/ULP-1 protease cleavage site, and a non-human Caspase 3 cleavage site. In other aspects of this embodiment, an exogenous protease cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G, a modified TeNT, a modified BaNT, or a modified BuNT.

In an aspect of this embodiment, an exogenous protease cleavage site can comprise, e.g., a non-human enterokinase cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can comprise, e.g., a bovine enterokinase protease cleavage site located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can comprise, e.g., a bovine enterokinase protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises SEQ ID NO: 21. In still other aspects of this embodiment, a bovine enterokinase protease cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G, a modified TeNT, a modified BaNT, or a modified BuNT.

In another aspect of this embodiment, an exogenous protease cleavage site can comprise, e.g., a Tobacco Etch Virus protease cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can comprise, e.g., a Tobacco Etch Virus protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises the consensus sequence E-P5-P4-Y-P2-Q*-G (SEQ ID NO: 22) or E-P5-P4-Y-P2-Q*-S (SEQ ID NO: 23), where P2, P4 and P5 can be any amino acid. In other aspects of the embodiment, an exogenous protease cleavage site can comprise, e.g., a Tobacco Etch Virus protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises SEQ ID NO: 24, SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 or SEQ ID NO: 33. In still other aspects of this embodiment, a Tobacco Etch Virus protease cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G, a modified TeNT, a modified BaNT, or a modified BuNT.

In another aspect of this embodiment, an exogenous protease cleavage site can comprise, e.g., a Tobacco Vein Mottling Virus protease cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can comprise, e.g., a Tobacco Vein Mottling Virus protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises the consensus sequence P6-P5-V-R-F-Q*-G (SEQ ID NO: 132) or P6-P5-V-R-F-Q*-S (SEQ ID NO: 133), where P5 and P6 can be any amino acid. In other aspects of the embodiment, an exogenous protease cleavage site can comprise, e.g., a Tobacco Vein Mottling Virus protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises SEQ ID NO: 134, SEQ ID NO: 135, SEQ ID NO: 136, or SEQ ID NO: 137. In still other aspects of this embodiment, a Tobacco Vein Mottling Virus protease cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G, a modified TeNT, a modified BaNT, or a modified BuNT.

In still another aspect of this embodiment, an exogenous protease cleavage site can comprise, e.g., a human rhinovirus 3C protease cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can comprise, e.g., a human rhinovirus 3C protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises the consensus sequence P5-P4-L-F-Q*-G-P (SEQ ID NO: 34), where P4 is G, A, V, L, I, M, S or T and P5 can any amino acid, with D or E preferred. In other aspects of the embodiment, an exogenous protease cleavage site can comprise, e.g., a human rhinovirus 3C protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39 or SEQ ID NO: 40. In other aspects of the embodiment, an exogenous protease cleavage site can comprise, e.g., a human rhinovirus 3C protease located within the di-chain loop of a modified Clostridial toxin that can be cleaved by PRESCISSION®. In still other aspects of this embodiment, a human rhinovirus 3C protease cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G, a modified TeNT, a modified BaNT, or a modified BuNT.

In yet another aspect of this embodiment, an exogenous protease cleavage site can comprise, e.g., a subtilisin cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can comprise, e.g., a subtilisin cleavage site located within the di-chain loop of a modified Clostridial toxin comprises the consensus sequence P6-P5-P4-P3-H*-Y (SEQ ID NO: 41) or P6-P5-P4-P3-Y-H* (SEQ ID NO: 42), where P3, P4 and P5 and P6 can be any amino acid. In other aspects of the embodiment, an exogenous protease cleavage site can comprise, e.g., a subtilisin cleavage site located within the di-chain loop of a modified Clostridial toxin comprises SEQ ID NO: 43, SEQ ID NO: 44, or SEQ ID NO: 45. In other aspects of the embodiment, an exogenous protease cleavage site can comprise, e.g., a subtilisin cleavage site located within the di-chain loop of a modified Clostridial toxin that can be cleaved by GENENASE®. In still other aspects of this embodiment, a subtilisin cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G, a modified TeNT, a modified BaNT, or a modified BuNT.

In yet another aspect of this embodiment, an exogenous protease cleavage site can comprise, e.g., a hydroxylamine cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can comprise, e.g., a hydroxylamine cleavage site comprising multiples of the dipeptide N*G. In other aspects of the embodiment, an exogenous protease cleavage site can comprise, e.g., a hydroxylamine cleavage site located within the di-chain loop of a modified Clostridial toxin comprises SEQ ID NO: 46, or SEQ ID NO: 47. In still other aspects of this embodiment, a hydroxylamine cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G, a modified TeNT, a modified BaNT, or a modified BuNT.

In yet another aspect of this embodiment, an exogenous protease cleavage site can comprise, e.g., a SUMO/ULP-1 protease cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can comprise, e.g., a SUMO/ULP-1 protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprising the consensus sequence G-G*-P1′-P2′-P3′ (SEQ ID NO: 131), where P1′, P2′, and P3′ can be any amino acid. In other aspects of the embodiment, an exogenous protease cleavage site can comprise, e.g., a SUMO/ULP-1 protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises SEQ ID NO: 48. In still other aspects of this embodiment, a SUMO/ULP-1 protease cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G, a modified TeNT, a modified BaNT, or a modified BuNT.

In an aspect of this embodiment, an exogenous protease cleavage site can comprise, e.g., a non-human Caspase 3 cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can comprise, e.g., a mouse Caspase 3 protease cleavage site located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can comprise, e.g., a non-human Caspase 3 protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises the consensus sequence D-P3-P2-D*P1′ (SEQ ID NO: 138), where P3 can be any amino acid, with E preferred, P2 can be any amino acid and P1′ can any amino acid, with G or S preferred. In other aspects of the embodiment, an exogenous protease cleavage site can comprise, e.g., a non-human Caspase 3 protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprising SEQ ID NO: 139, SEQ ID NO: 140, SEQ ID NO: 141, SEQ ID NO: 142, SEQ ID NO: 143 or SEQ ID NO: 144. In still other aspects of this embodiment, a bovine enterokinase protease cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G, a modified TeNT, a modified BaNT, or a modified BuNT.

A di-chain loop region is modified to replace a naturally-occurring di-chain loop protease cleavage site for an exogenous protease cleavage site. In this modification, the naturally-occurring di-chain loop protease cleavage site is made inoperable and thus can not be cleaved by its protease. Only the exogenous protease cleavage site can be cleaved by its corresponding exogenous protease. In this type of modification, the exogenous protease site is operably-linked in-frame to a modified Clostridial toxin as a fusion protein and the site can be cleaved by its respective exogenous protease. Replacement of an endogenous di-chain loop protease cleavage site with an exogenous protease cleavage site can be a substitution of the sites where the exogenous site is engineered at the position approximating the cleavage site location of the endogenous site. Replacement of an endogenous di-chain loop protease cleavage site with an exogenous protease cleavage site can be an addition of an exogenous site where the exogenous site is engineered at the position different from the cleavage site location of the endogenous site, the endogenous site being engineered to be inoperable. The location and kind of protease cleavage site may be critical because certain binding domains require a free amino-terminal or carboxyl-terminal amino acid. For example, when a binding domain is placed between two other domains, e.g., see FIG. 22, a criterion for selection of a protease cleavage site could be whether the protease that cleaves its site leaves a flush cut, exposing the free amino-terminal or carboxyl-terminal of the binding domain necessary for selective binding of the binding domain to its receptor.

A naturally-occurring protease cleavage site can be made inoperable by altering at least the two amino acids flanking the peptide bond cleaved by the naturally-occurring di-chain loop protease. More extensive alterations can be made, with the proviso that the two cysteine residues of the di-chain loop region remain intact and the region can still form the disulfide bridge. Non-limiting examples of an amino acid alteration include deletion of an amino acid or replacement of the original amino acid with a different amino acid. Thus, in one embodiment, a naturally-occurring protease cleavage site is made inoperable by altering the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease. In other aspects of this embodiment, a naturally-occurring protease cleavage site is made inoperable by altering, e.g., at least three amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least four amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least five amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least six amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least seven amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least eight amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least nine amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least ten amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least 15 amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; or at least 20 amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease.

In still other aspects of this embodiment, a naturally-occurring di-chain protease cleavage site is made inoperable by altering, e.g., at most three amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most four amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most five amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most six amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most seven amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most eight amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most nine amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most ten amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most 15 amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; or at most 20 amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease.

It is understood that a modified Clostridial toxin disclosed in the present specification can optionally further comprise a flexible region comprising a flexible spacer. Non-limiting examples of a flexible spacer include, e.g., a G-spacer GGGGS (SEQ ID NO: 49) or an A-spacer EAAAK (SEQ ID NO: 50). A flexible region comprising flexible spacers can be used to adjust the length of a polypeptide region in order to optimize a characteristic, attribute or property of a polypeptide. Such a flexible region is operably-linked in-frame to the modified Clostridial toxin as a fusion protein. As a non-limiting example, a polypeptide region comprising one or more flexible spacers in tandem can be use to better expose a protease cleavage site thereby facilitating cleavage of that site by a protease. As another non-limiting example, a polypeptide region comprising one or more flexible spacers in tandem can be use to better present a binding domain, thereby facilitating the binding of that binding domain to its receptor.

Thus, in an embodiment, a modified Clostridial toxin disclosed in the present specification can further comprise a flexible region comprising a flexible spacer. In another embodiment, a modified Clostridial toxin disclosed in the present specification can further comprise flexible region comprising a plurality of flexible spacers in tandem. In aspects of this embodiment, a flexible region can comprise in tandem, e.g., at least 1 G-spacer, at least 2 G-spacers, at least 3 G-spacers, at least 4 G-spacers or at least 5 G-spacers. In other aspects of this embodiment, a flexible region can comprise in tandem, e.g., at most 1 G-spacer, at most 2 G-spacers, at most 3 G-spacers, at most 4 G-spacers or at most 5 G-spacers. In still other aspects of this embodiment, a flexible region can comprise in tandem, e.g., at least 1 A-spacer, at least 2 A-spacers, at least 3 A-spacers, at least 4 A-spacers or at least 5 A-spacers. In still other aspects of this embodiment, a flexible region can comprise in tandem, e.g., at most 1 A-spacer, at most 2 A-spacers, at most 3 A-spacers, at most 4 A-spacers or at most 5 A-spacers. In another aspect of this embodiment, a modified Clostridial toxin can comprise a flexible region comprising one or more copies of the same flexible spacers, one or more copies of different flexible-spacer regions, or any combination thereof.

In other aspects of this embodiment, a modified Clostridial toxin comprising a flexible spacer can be, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G, a modified TeNT, a modified BaNT, or a modified BuNT.

It is envisioned that a modified Clostridial toxin disclosed in the present specification can comprise a flexible spacer in any and all locations with the proviso that modified Clostridial toxin is capable of performing the intoxication process. In aspects of this embodiment, a flexible spacer is positioned between, e.g., a therapeutic element and a translocation element, a therapeutic element and a binding element, a therapeutic element and an exogenous protease cleavage site. In other aspects of this embodiment, a G-spacer is positioned between, e.g., a therapeutic element and a translocation element, a therapeutic element and a binding element, a therapeutic element and an exogenous protease cleavage site. In other aspects of this embodiment, an A-spacer is positioned between, e.g., a therapeutic element and a translocation element, a therapeutic element and a binding element, a therapeutic element and an exogenous protease cleavage site.

In other aspects of this embodiment, a flexible spacer is positioned between, e.g., a binding element and a translocation element, a binding element and a therapeutic element, a binding element and an exogenous protease cleavage site. In other aspects of this embodiment, a G-spacer is positioned between, e.g., a binding element and a translocation element, a binding element and a therapeutic element, a binding element and an exogenous protease cleavage site. In other aspects of this embodiment, an A-spacer is positioned between, e.g., a binding element and a translocation element, a binding element and a therapeutic element, a binding element and an exogenous protease cleavage site.

In yet other aspects of this embodiment, a flexible spacer is positioned between, e.g., a translocation element and a therapeutic element, a translocation element and a binding element, a translocation element and an exogenous protease cleavage site. In other aspects of this embodiment, a G-spacer is positioned between, e.g., a translocation element and a therapeutic element, a translocation element and a binding element, a translocation element and an exogenous protease cleavage site. In other aspects of this embodiment, an A-spacer is positioned between, e.g., a translocation element and a therapeutic element, a translocation element and a binding element, a translocation element and an exogenous protease cleavage site.

In another aspect, the invention is drawn to recombinant single-chain modified clostridial neurotoxins that may be cleaved at will by a protease to provide an active di-chain molecule. Such modified neurotoxins need not be toxic; in certain of these proteins the enzymatic activity of the toxin L chain may be abrogated, and the toxin joined to a drug or other bioactive agent having therapeutic activity. Alternatively, in certain other modified neurotoxins the L chain is enzymatically active, but portions of the H chain are modified to provide specificity to target cells other than the natural target of the neurotoxin, while maintaining the translocation and endocytosis-stimulating activities of the native toxin. Modified neurotoxins such as those described in this aspect of the invention are disclosed in, for example, Dolly et al., Modified Clostridial Toxins for Use as Transport Proteins, International Patent Publication WO 95/32738 (Dec. 7, 1995); Foster et al., Botulinum Toxin Derivatives Able to Modify Peripheral Sensory Afferent Functions, International Patent Publication WO96/33273 (Oct. 24, 1996); Shone et al., Recombinant Toxin Fragments, International Patent Application WO 98/07864 (98/07864); and Duggan and Chaddock, Conjugates of Galactose-Binding Lectins and Clostridial Neurotoxins as Analgesics, International Patent Publication WO 99/17806 (Apr. 15, 1999); Dolly et al., Compositions and Methods for Extending the Action of Clostridial Neurotoxin, International Patent Publication WO 99/55359 (Nov. 4, 1999); Keith A. Foster et al., Clostridial Toxin Derivatives Able To Modify Peripheral Sensory Afferent Functions, U.S. Pat. No. 5,989,545 (Nov. 23, 1999); Clifford C. Shone et al., Recombinant Toxin Fragments, U.S. Pat. No. 6,461,617 (Oct. 8, 2002); Conrad P. Quinn et al., Methods and Compounds for the Treatment of Mucus Hypersecretion, U.S. Pat. No. 6,632,440 (Oct. 14, 2003); Lance E. Steward et al., Methods And Compositions For The Treatment Of Pancreatitis, U.S. Pat. No. 6,843,998 (Jan. 18, 2005); Stephan Donovan, Clostridial Toxin Derivatives and Methods For Treating Pain, U.S. Pat. No. 7,138,127 (Nov. 21, 2006); Keith A. Foster et al., Inhibition of Secretion from Non-Neural Cells, U.S. Patent Publication 2003/0180289 (Sep. 25, 2003); these publications are incorporated by reference herein. The present invention provides single-chain, cleavable versions of these molecules and improved methods of making such molecules.

In another aspect, the invention comprises a modified clostridial neurotoxin derived from tetanus toxin (TeNT), or one or more of the botulinum toxin (BoNT) subtypes in which the naturally-occurring interchain loop region has been replace with a modified loop region comprising a different amino acid sequence conferring 1) resistance to cleavage by host proteases or autolytic action, and/or 2) lability to a selected protease. Preferably the cleavage site is highly specific for the selected protease. The interchain loop region of certain clostridial neurotoxins, for example, BoNT/E, is naturally resistant to proteolytic cleavage in vivo. This protease resistance may reflect a secondary or tertiary structure that makes the loop more resistant to indigenous proteases than other clostridial neurotoxins. In one embodiment of the present invention, therefore, the inter-chain loop region of BoNT/E is substituted for the natural loop region occurring an another BoNT having greater therapeutic activity or duration of action, for example BoNT/A or /B. In another embodiment of the invention the loop region of BoNT/E is modified to contain a proteolytic cleavage site highly specific to a selected protease prior to the subcloning. The otherwise highly conserved BoNT/E loop region would be resistant to indigenous proteases, or those encountered within a human, but would retain the ability to be activated by digestion with the selected protease.

Unless indicated otherwise, the following terms have the following meanings in this specification:

The “therapeutic element” of the present invention may comprise, without limitation: active or inactive (i.e., modified) hormone receptors (such as androgen, estrogen, retinoid, perioxysome proliferator and ecdysone receptors etc.), and hormone-agonists and antagonists, nucleic acids capable being of being used as replication, transcription, or translational templates (e.g., for expression of a protein drug having the desired biological activity or for synthesis of a nucleic acid drug as an antisense agent), enzymes, toxins (including apoptosis-inducing or -preventing agents), and the like.

In a preferred embodiment, the therapeutic element is a polypeptide comprising a clostridial neurotoxin light chain or a portion thereof retaining the SNARE-protein sequence-specific endopeptidase activity of a clostridial neurotoxin light chain. The amino acid sequences of the light chain of botulinum neurotoxin (BoNT) subtypes A-G have been determined, as has the amino acid sequence of the light chains of the tetanus neurotoxin (TeNT), Baratii neurotoxin (BaNT), and butyricum neurotoxin (BuNT). Each chain contains the Zn⁺⁺-binding motif His-Glu-Xaa-Xaa-His (SEQ ID NO: 51).

Recent studies of the BoNT/A light chain have revealed certain features important for the activity and specificity of the toxin towards its target substrate, SNAP-25. Thus, studies by Zhou et al. Biochemistry 34:15175-15181 (1995) have indicated that when the light chain amino acid residue His₂₂₇ is substituted with tyrosine, the resulting polypeptide is unable to cleave SNAP-25; Kurazono et al., J. Biol. Chem. 14721-14729 (1992) performed studies in the presynaptic cholinergic neurons of the buccal ganglia of Aplysia californica using recombinant BoNT/A light chain that indicated that the removal of 8 N-terminal or 32 C-terminal residues did not abolish toxicity, but that removal of 10 N-terminal or 57 C-terminal residues abolished toxicity in this system. Most recently, the crystal structure of the entire BoNT/A holotoxin has been solved; the active site is indicated as involving the participation of His₂₂₂, Glu₂₂₃, His₂₂₆, Glu₂₆, and Tyr₃₆₅. Lacy et al., supra. (These residues correspond to His₂₂₃, Glu₂₂₄, His₂₂₇, Glu₂₆₂ and Tyr₃₆₆ of the BoNT/A L chain of Kurazono et al., supra.) Interestingly, an alignment of BoNT/A through E and TeNT light chains reveals that every such chain invariably has these residues in positions analogous to BoNT/A. Kurazono et al., supra.

The catalytic domain of BoNT/A is very specific for the C-terminus of SNAP-25 and appears to require a minimum of 17 SNAP-25 amino acids for cleavage to occur. The catalytic site resembles a pocket; when the light chained is linked to the heavy chain via the disulfide bond between Cys₄₂₉ and Cys₄₅₃, the translocation domain of the heavy chain appears to block access to the catalytic pocket until the light chain gains entry to the cytosol. When the disulfide bond is then reduced, the catalytic pocket is “opened” and the light chain is fully active.

The substrate specificities of the various clostridial neurotoxin light chains other than BoNT/A are known. As described above, VAMP and syntaxin are cleaved by BoNT/B, D, F, G and TeNT, and BoNT/C₁, respectively, while SNAP-25 is cleaved by BoNT/A E and C1. Therefore, the person of ordinary skill in the art could easily determine the toxin residues essential in these subtypes for cleavage and substrate recognition (for example, by site-directed mutagenesis or deletion of various regions of the toxin molecule followed by testing of proteolytic activity and substrate specificity), and could therefore easily design variants of the native neurotoxin light chain that retain or lack the same or similar activity.

Aspects of the present invention provide, in part, a Clostridial toxin enzymatic domain. As used herein, the term “Clostridial toxin enzymatic domain” means any Clostridial toxin polypeptide that can execute the enzymatic target modification step of the intoxication process. Thus, a Clostridial toxin enzymatic domain specifically targets a Clostridial toxin substrate and encompasses the proteolytic cleavage of a Clostridial toxin substrate, such as, e.g., SNARE proteins like a SNAP-25 substrate, a VAMP substrate and a Syntaxin substrate. Non-limiting examples of a Clostridial toxin enzymatic domain include, e.g., a BoNT/A enzymatic domain, a BoNT/B enzymatic domain, a BoNT/C1 enzymatic domain, a BoNT/D enzymatic domain, a BoNT/E enzymatic domain, a BoNT/F enzymatic domain, a BoNT/G enzymatic domain, a TeNT enzymatic domain, a BaNT enzymatic domain, and a BuNT enzymatic domain. Other non-limiting examples of a Clostridial toxin enzymatic domain include, e.g., amino acids 1-448 of SEQ ID NO: 1, amino acids 1-441 of SEQ ID NO: 2, amino acids 1-449 of SEQ ID NO: 3, amino acids 1-445 of SEQ ID NO: 4, amino acids 1-422 of SEQ ID NO: 5, amino acids 1-439 of SEQ ID NO: 6, amino acids 1-446 of SEQ ID NO: 7, amino acids 1-457 of SEQ ID NO: 8, amino acids 1-431 of SEQ ID NO: 9, and amino acids 1-422 of SEQ ID NO: 10.

A Clostridial toxin enzymatic domain includes, without limitation, naturally occurring Clostridial toxin enzymatic domain variants, such as, e.g., Clostridial toxin enzymatic domain isoforms and Clostridial toxin enzymatic domain subtypes; non-naturally occurring Clostridial toxin enzymatic domain variants, such as, e.g., conservative Clostridial toxin enzymatic domain variants, non-conservative Clostridial toxin enzymatic domain variants, Clostridial toxin enzymatic domain chimerics, active Clostridial toxin enzymatic domain fragments thereof, or any combination thereof.

As used herein, the term “Clostridial toxin enzymatic domain variant,” whether naturally-occurring or non-naturally-occurring, means a Clostridial toxin enzymatic domain that has at least one amino acid change from the corresponding region of the disclosed reference sequences (Table 1) and can be described in percent identity to the corresponding region of that reference sequence. Unless expressly indicated, all Clostridial toxin enzymatic domain variants disclosed in the present specification are capable of executing the enzymatic target modification step of the intoxication process. As non-limiting examples, a BoNT/A enzymatic domain variant comprising amino acids 1-448 of SEQ ID NO: 1 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-448 of SEQ ID NO: 1; a BoNT/B enzymatic domain variant comprising amino acids 1-441 of SEQ ID NO: 2 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-441 of SEQ ID NO: 2; a BoNT/C1 enzymatic domain variant comprising amino acids 1-449 of SEQ ID NO: 3 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-449 of SEQ ID NO: 3; a BoNT/D enzymatic domain variant comprising amino acids 1-445 of SEQ ID NO: 4 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-445 of SEQ ID NO: 4; a BoNT/E enzymatic domain variant comprising amino acids 1-422 of SEQ ID NO: 5 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-422 of SEQ ID NO: 5; a BoNT/F enzymatic domain variant comprising amino acids 1-439 of SEQ ID NO: 6 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-439 of SEQ ID NO: 6; a BoNT/G enzymatic domain variant comprising amino acids 1-446 of SEQ ID NO: 7 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-446 of SEQ ID NO: 7; and a TeNT enzymatic domain variant comprising amino acids 1-457 of SEQ ID NO: 8 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-457 of SEQ ID NO: 8.

It is recognized by those of skill in the art that within each serotype of Clostridial toxin there can be naturally occurring Clostridial toxin enzymatic domain variants that differ somewhat in their amino acid sequence, and also in the nucleic acids encoding these proteins. For example, there are presently four BoNT/A subtypes, BoNT/A1, BoNT/A2, BoNT/A3 and BoNT/A4, with specific enzymatic domain subtypes showing approximately 95% amino acid identity when compared to another BoNT/A enzymatic domain subtype. As used herein, the term “naturally occurring Clostridial toxin enzymatic domain variant” means any Clostridial toxin enzymatic domain produced by a naturally-occurring process, including, without limitation, Clostridial toxin enzymatic domain isoforms produced from alternatively-spliced transcripts, Clostridial toxin enzymatic domain isoforms produced by spontaneous mutation and Clostridial toxin enzymatic domain subtypes. A naturally occurring Clostridial toxin enzymatic domain variant can function in substantially the same manner as the reference Clostridial toxin enzymatic domain on which the naturally occurring Clostridial toxin enzymatic domain variant is based, and can be substituted for the reference Clostridial toxin enzymatic domain in any aspect of the present invention. A naturally occurring Clostridial toxin enzymatic domain variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids or 100 or more amino acids from the reference Clostridial toxin enzymatic domain on which the naturally occurring Clostridial toxin enzymatic domain variant is based. A naturally occurring Clostridial toxin enzymatic domain variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin enzymatic domain on which the naturally occurring Clostridial toxin enzymatic domain variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin enzymatic domain on which the naturally occurring Clostridial toxin enzymatic domain variant is based.

A non-limiting examples of a naturally occurring Clostridial toxin enzymatic domain variant is a Clostridial toxin enzymatic domain isoform such as, e.g., a BoNT/A enzymatic domain isoform, a BoNT/B enzymatic domain isoform, a BoNT/C1 enzymatic domain isoform, a BoNT/D enzymatic domain isoform, a BoNT/E enzymatic domain isoform, a BoNT/F enzymatic domain isoform, a BoNT/G enzymatic domain isoform, and a TeNT enzymatic domain isoform. A Clostridial toxin enzymatic domain isoform can function in substantially the same manner as the reference Clostridial toxin enzymatic domain on which the Clostridial toxin enzymatic domain isoform is based, and can be substituted for the reference Clostridial toxin enzymatic domain in any aspect of the present invention.

Another non-limiting examples of a naturally occurring Clostridial toxin enzymatic domain variant is a Clostridial toxin enzymatic domain subtype such as, e.g., a enzymatic domain from subtype BoNT/A1, BoNT/A2, BoNT/A3 and BoNT/A4; a enzymatic domain from subtype BoNT/B1, BoNT/B2, BoNT/B bivalent and BoNT/B nonproteolytic; a enzymatic domain from subtype BoNT/C1-1 and BoNT/C1-2; a enzymatic domain from subtype BoNT/E1, BoNT/E2 and BoNT/E3; and a enzymatic domain from subtype BoNT/F1, BoNT/F2, BoNT/F3 and BoNT/F4. A Clostridial toxin enzymatic domain subtype can function in substantially the same manner as the reference Clostridial toxin enzymatic domain on which the Clostridial toxin enzymatic domain subtype is based, and can be substituted for the reference Clostridial toxin enzymatic domain in any aspect of the present invention.

As used herein, the term “non-naturally occurring Clostridial toxin enzymatic domain variant” means any Clostridial toxin enzymatic domain produced with the aid of human manipulation, including, without limitation, Clostridial toxin enzymatic domains produced by genetic engineering using random mutagenesis or rational design and Clostridial toxin enzymatic domains produced by chemical synthesis. Non-limiting examples of non-naturally occurring Clostridial toxin enzymatic domain variants include, e.g., conservative Clostridial toxin enzymatic domain variants, non-conservative Clostridial toxin enzymatic domain variants, Clostridial toxin enzymatic domain chimeric variants and active Clostridial toxin enzymatic domain fragments.

As used herein, the term “conservative Clostridial toxin enzymatic domain variant” means a Clostridial toxin enzymatic domain that has at least one amino acid substituted by another amino acid or an amino acid analog that has at least one property similar to that of the original amino acid from the reference Clostridial toxin enzymatic domain sequence (Table 1). Examples of properties include, without limitation, similar size, topography, charge, hydrophobicity, hydrophilicity, lipophilicity, covalent-bonding capacity, hydrogen-bonding capacity, a physicochemical property, of the like, or any combination thereof. A conservative Clostridial toxin enzymatic domain variant can function in substantially the same manner as the reference Clostridial toxin enzymatic domain on which the conservative Clostridial toxin enzymatic domain variant is based, and can be substituted for the reference Clostridial toxin enzymatic domain in any aspect of the present invention. A conservative Clostridial toxin enzymatic domain variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids, 100 or more amino acids, 200 or more amino acids, 300 or more amino acids, 400 or more amino acids, or 500 or more amino acids from the reference Clostridial toxin enzymatic domain on which the conservative Clostridial toxin enzymatic domain variant is based. A conservative Clostridial toxin enzymatic domain variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin enzymatic domain on which the conservative Clostridial toxin enzymatic domain variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin enzymatic domain on which the conservative Clostridial toxin enzymatic domain variant is based. Non-limiting examples of a conservative Clostridial toxin enzymatic domain variant include, e.g., conservative BoNT/A enzymatic domain variants, conservative BoNT/B enzymatic domain variants, conservative BoNT/C1 enzymatic domain variants, conservative BoNT/D enzymatic domain variants, conservative BoNT/E enzymatic domain variants, conservative BoNT/F enzymatic domain variants, conservative BoNT/G enzymatic domain variants, and conservative TeNT enzymatic domain variants.

As used herein, the term “non-conservative Clostridial toxin enzymatic domain variant” means a Clostridial toxin enzymatic domain in which 1) at least one amino acid is deleted from the reference Clostridial toxin enzymatic domain on which the non-conservative Clostridial toxin enzymatic domain variant is based; 2) at least one amino acid added to the reference Clostridial toxin enzymatic domain on which the non-conservative Clostridial toxin enzymatic domain is based; or 3) at least one amino acid is substituted by another amino acid or an amino acid analog that does not share any property similar to that of the original amino acid from the reference Clostridial toxin enzymatic domain sequence (Table 1). A non-conservative Clostridial toxin enzymatic domain variant can function in substantially the same manner as the reference Clostridial toxin enzymatic domain on which the non-conservative Clostridial toxin enzymatic domain variant is based, and can be substituted for the reference Clostridial toxin enzymatic domain in any aspect of the present invention. A non-conservative Clostridial toxin enzymatic domain variant can delete one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids from the reference Clostridial toxin enzymatic domain on which the non-conservative Clostridial toxin enzymatic domain variant is based. A non-conservative Clostridial toxin enzymatic domain variant can add one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids to the reference Clostridial toxin enzymatic domain on which the non-conservative Clostridial toxin enzymatic domain variant is based. A non-conservative Clostridial toxin enzymatic domain variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids, 100 or more amino acids, 200 or more amino acids, 300 or more amino acids, 400 or more amino acids, or 500 or more amino acids from the reference Clostridial toxin enzymatic domain on which the non-conservative Clostridial toxin enzymatic domain variant is based. A non-conservative Clostridial toxin enzymatic domain variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin enzymatic domain on which the non-conservative Clostridial toxin enzymatic domain variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin enzymatic domain on which the non-conservative Clostridial toxin enzymatic domain variant is based. Non-limiting examples of a non-conservative Clostridial toxin enzymatic domain variant include, e.g., non-conservative BoNT/A enzymatic domain variants, non-conservative BoNT/B enzymatic domain variants, non-conservative BoNT/C1 enzymatic domain variants, non-conservative BoNT/D enzymatic domain variants, non-conservative BoNT/E enzymatic domain variants, non-conservative BoNT/F enzymatic domain variants, non-conservative BoNT/G enzymatic domain variants, and non-conservative TeNT enzymatic domain variants.

As used herein, the term “Clostridial toxin enzymatic domain chimeric” means a polypeptide comprising at least a portion of a Clostridial toxin enzymatic domain and at least a portion of at least one other polypeptide to form a toxin enzymatic domain with at least one property different from the reference Clostridial toxin enzymatic domains of Table 1, with the proviso that this Clostridial toxin enzymatic domain chimeric is still capable of specifically targeting the core components of the neurotransmitter release apparatus and thus participate in executing the overall cellular mechanism whereby a Clostridial toxin proteolytically cleaves a substrate. Such Clostridial toxin enzymatic domain chimerics are described in, e.g., Lance E. Steward et al., Leucine-based Motif and Clostridial Toxins, U.S. Patent Publication 2003/0027752 (Feb. 6, 2003); Lance E. Steward et al., Clostridial Neurotoxin Compositions and Modified Clostridial Neurotoxins, U.S. Patent Publication 2003/0219462 (Nov. 27, 2003); and Lance E. Steward et al., Clostridial Neurotoxin Compositions and Modified Clostridial Neurotoxins, U.S. Patent Publication 2004/0220386 (Nov. 4, 2004), each of which is incorporated by reference in its entirety.

As used herein, the term “active Clostridial toxin enzymatic domain fragment” means any of a variety of Clostridial toxin fragments comprising the enzymatic domain can be useful in aspects of the present invention with the proviso that these enzymatic domain fragments can specifically target the core components of the neurotransmitter release apparatus and thus participate in executing the overall cellular mechanism whereby a Clostridial toxin proteolytically cleaves a substrate. The enzymatic domains of Clostridial toxins are approximately 420-460 amino acids in length and comprise an enzymatic domain (Table 1). Research has shown that the entire length of a Clostridial toxin enzymatic domain is not necessary for the enzymatic activity of the enzymatic domain. As a non-limiting example, the first eight amino acids of the BoNT/A enzymatic domain (residues 1-8 of SEQ ID NO: 1) are not required for enzymatic activity. As another non-limiting example, the first eight amino acids of the TeNT enzymatic domain (residues 1-8 of SEQ ID NO: 8) are not required for enzymatic activity. Likewise, the carboxyl-terminus of the enzymatic domain is not necessary for activity. As a non-limiting example, the last 32 amino acids of the BoNT/A enzymatic domain (residues 417-448 of SEQ ID NO: 1) are not required for enzymatic activity. As another non-limiting example, the last 31 amino acids of the TeNT enzymatic domain (residues 427-457 of SEQ ID NO: 8) are not required for enzymatic activity. Thus, aspects of this embodiment can include Clostridial toxin enzymatic domains comprising an enzymatic domain having a length of, e.g., at least 350 amino acids, at least 375 amino acids, at least 400 amino acids, at least 425 amino acids and at least 450 amino acids. Other aspects of this embodiment can include Clostridial toxin enzymatic domains comprising an enzymatic domain having a length of, e.g., at most 350 amino acids, at most 375 amino acids, at most 400 amino acids, at most 425 amino acids and at most 450 amino acids.

Any of a variety of sequence alignment methods can be used to determine percent identity of naturally-occurring Clostridial toxin enzymatic domain variants and non-naturally-occurring Clostridial toxin enzymatic domain variants, including, without limitation, global methods, local methods and hybrid methods, such as, e.g., segment approach methods. Protocols to determine percent identity are routine procedures within the scope of one skilled in the art and from the teaching herein.

Global methods align sequences from the beginning to the end of the molecule and determine the best alignment by adding up scores of individual residue pairs and by imposing gap penalties. Non-limiting methods include, e.g., CLUSTAL W, see, e.g., Julie D. Thompson et al., CLUSTAL W: Improving the Sensitivity of Progressive Multiple Sequence Alignment Through Sequence Weighting, Position-Specific Gap Penalties and Weight Matrix Choice, 22(22) Nucleic Acids Research 4673-4680 (1994); and iterative refinement, see, e.g., Osamu Gotoh, Significant Improvement in Accuracy of Multiple Protein Sequence Alignments by Iterative Refinement as Assessed by Reference to Structural Alignments, 264(4) J. Mol. Biol. 823-838 (1996).

Local methods align sequences by identifying one or more conserved motifs shared by all of the input sequences. Non-limiting methods include, e.g., Match-box, see, e.g., Eric Depiereux and Ernest Feytmans, Match-Box: A Fundamentally New Algorithm for the Simultaneous Alignment of Several Protein Sequences, 8(5) CABIOS 501-509 (1992); Gibbs sampling, see, e.g., C. E. Lawrence et al., Detecting Subtle Sequence Signals: A Gibbs Sampling Strategy for Multiple Alignment, 262(5131) Science 208-214 (1993); Align-M, see, e.g., Ivo Van Walle et al., Align-M—A New Algorithm for Multiple Alignment of Highly Divergent Sequences, 20(9) Bioinformatics: 1428-1435 (2004).

Hybrid methods combine functional aspects of both global and local alignment methods. Non-limiting methods include, e.g., segment-to-segment comparison, see, e.g., Burkhard Morgenstern et al., Multiple DNA and Protein Sequence Alignment Based On Segment-To-Segment Comparison, 93(22) Proc. Natl. Acad. Sci. U.S.A. 12098-12103 (1996); T-Coffee, see, e.g., Cédric Notredame et al., T-Coffee: A Novel Algorithm for Multiple Sequence Alignment, 302(1) J. Mol. Biol. 205-217 (2000); MUSCLE, see, e.g., Robert C. Edgar, MUSCLE: Multiple Sequence Alignment With High Score Accuracy and High Throughput, 32(5) Nucleic Acids Res. 1792-1797 (2004); and DIALIGN-T, see, e.g., Amarendran R Subramanian et al., DIALIGN-T: An Improved Algorithm for Segment-Based Multiple Sequence Alignment, 6(1) BMC Bioinformatics 66 (2005).

Thus, in an embodiment, a modified Clostridial toxin disclosed in the present specification comprises a Clostridial toxin enzymatic domain. In an aspect of this embodiment, a Clostridial toxin enzymatic domain comprises a naturally occurring Clostridial toxin enzymatic domain variant, such as, e.g., a Clostridial toxin enzymatic domain isoform or a Clostridial toxin enzymatic domain subtype. In another aspect of this embodiment, a Clostridial toxin enzymatic domain comprises a non-naturally occurring Clostridial toxin enzymatic domain variant, such as, e.g., a conservative Clostridial toxin enzymatic domain variant, a non-conservative Clostridial toxin enzymatic domain variant, a Clostridial toxin chimeric enzymatic domain, an active Clostridial toxin enzymatic domain fragment, or any combination thereof.

In another embodiment, a Clostridial toxin enzymatic domain comprises a BoNT/A enzymatic domain. In an aspect of this embodiment, a BoNT/A enzymatic domain comprises amino acids 1-448 of SEQ ID NO: 1. In another aspect of this embodiment, a BoNT/A enzymatic domain comprises a naturally occurring BoNT/A enzymatic domain variant, such as, e.g., a enzymatic domain from a BoNT/A isoform or a enzymatic domain from a BoNT/A subtype. In another aspect of this embodiment, a BoNT/A enzymatic domain comprises amino acids 1-448 of a naturally occurring BoNT/A enzymatic domain variant of SEQ ID NO: 1, such as, e.g., amino acids 1-448 of a BoNT/A isoform of SEQ ID NO: 1 or amino acids 1-448 of a BoNT/A subtype of SEQ ID NO: 1. In still another aspect of this embodiment, a BoNT/A enzymatic domain comprises a non-naturally occurring BoNT/A enzymatic domain variant, such as, e.g., a conservative BoNT/A enzymatic domain variant, a non-conservative BoNT/A enzymatic domain variant, a BoNT/A chimeric enzymatic domain, an active BoNT/A enzymatic domain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/A enzymatic domain comprises amino acids 1-448 of a non-naturally occurring BoNT/A enzymatic domain variant of SEQ ID NO: 1, such as, e.g., amino acids 1-448 of a conservative BoNT/A enzymatic domain variant of SEQ ID NO: 1, amino acids 1-448 of a non-conservative BoNT/A enzymatic domain variant of SEQ ID NO: 1, amino acids 1-448 of an active BoNT/A enzymatic domain fragment of SEQ ID NO: 1, or any combination thereof.

In other aspects of this embodiment, a BoNT/A enzymatic domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1-448 of SEQ ID NO: 1, at least 75% amino acid identity with amino acids 1-448 of SEQ ID NO: 1, at least 80% amino acid identity with amino acids 1-448 of SEQ ID NO: 1, at least 85% amino acid identity with amino acids 1-448 of SEQ ID NO: 1, at least 90% amino acid identity with amino acids 1-448 of SEQ ID NO: 1 or at least 95% amino acid identity with amino acids 1-448 of SEQ ID NO: 1. In yet other aspects of this embodiment, a BoNT/A enzymatic domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1-448 of SEQ ID NO: 1, at most 75% amino acid identity with amino acids 1-448 of SEQ ID NO: 1, at most 80% amino acid identity with amino acids 1-448 of SEQ ID NO: 1, at most 85% amino acid identity with amino acids 1-448 of SEQ ID NO: 1, at most 90% amino acid identity with amino acids 1-448 of SEQ ID NO: 1 or at most 95% amino acid identity with amino acids 1-448 of SEQ ID NO: 1.

In other aspects of this embodiment, a BoNT/A enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 1-448 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 1-448 of SEQ ID NO: 1. In yet other aspects of this embodiment, a BoNT/A enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-448 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-448 of SEQ ID NO: 1. In still other aspects of this embodiment, a BoNT/A enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-448 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-448 of SEQ ID NO: 1.

In other aspects of this embodiment, a BoNT/A enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-448 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-448 of SEQ ID NO: 1. In yet other aspects of this embodiment, a BoNT/A enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-448 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-448 of SEQ ID NO: 1. In still other aspects of this embodiment, a BoNT/A enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-448 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-448 of SEQ ID NO: 1.

In another embodiment, a Clostridial toxin enzymatic domain comprises a BoNT/B enzymatic domain. In an aspect of this embodiment, a BoNT/B enzymatic domain comprises amino acids 1-441 of SEQ ID NO: 2. In another aspect of this embodiment, a BoNT/B enzymatic domain comprises a naturally occurring BoNT/B enzymatic domain variant, such as, e.g., a enzymatic domain from a BoNT/B isoform or a enzymatic domain from a BoNT/B subtype. In another aspect of this embodiment, a BoNT/B enzymatic domain comprises amino acids 1-441 of a naturally occurring BoNT/B enzymatic domain variant of SEQ ID NO: 2, such as, e.g., amino acids 1-441 of a BoNT/B isoform of SEQ ID NO: 2 or amino acids 1-441 of a BoNT/B subtype of SEQ ID NO: 2. In still another aspect of this embodiment, a BoNT/B enzymatic domain comprises a non-naturally occurring BoNT/B enzymatic domain variant, such as, e.g., a conservative BoNT/B enzymatic domain variant, a non-conservative BoNT/B enzymatic domain variant, a BoNT/B chimeric enzymatic domain, an active BoNT/B enzymatic domain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/B enzymatic domain comprises amino acids 1-441 of a non-naturally occurring BoNT/B enzymatic domain variant of SEQ ID NO: 2, such as, e.g., amino acids 1-441 of a conservative BoNT/B enzymatic domain variant of SEQ ID NO: 2, amino acids 1-441 of a non-conservative BoNT/B enzymatic domain variant of SEQ ID NO: 2, amino acids 1-441 of an active BoNT/B enzymatic domain fragment of SEQ ID NO: 2, or any combination thereof.

In other aspects of this embodiment, a BoNT/B enzymatic domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1-441 of SEQ ID NO: 2, at least 75% amino acid identity with amino acids 1-441 of SEQ ID NO: 2, at least 80% amino acid identity with amino acids 1-441 of SEQ ID NO: 2, at least 85% amino acid identity with amino acids 1-441 of SEQ ID NO: 2, at least 90% amino acid identity with amino acids 1-441 of SEQ ID NO: 2 or at least 95% amino acid identity with amino acids 1-441 of SEQ ID NO: 2. In yet other aspects of this embodiment, a BoNT/B enzymatic domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1-441 of SEQ ID NO: 2, at most 75% amino acid identity with amino acids 1-441 of SEQ ID NO: 2, at most 80% amino acid identity with amino acids 1-441 of SEQ ID NO: 2, at most 85% amino acid identity with amino acids 1-441 of SEQ ID NO: 2, at most 90% amino acid identity with amino acids 1-441 of SEQ ID NO: 2 or at most 95% amino acid identity with amino acids 1-441 of SEQ ID NO: 2.

In other aspects of this embodiment, a BoNT/B enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 1-441 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 1-441 of SEQ ID NO: 2. In yet other aspects of this embodiment, a BoNT/B enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-441 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-441 of SEQ ID NO: 2. In still other aspects of this embodiment, a BoNT/B enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-441 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-441 of SEQ ID NO: 2.

In other aspects of this embodiment, a BoNT/B enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-441 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-441 of SEQ ID NO: 2. In yet other aspects of this embodiment, a BoNT/B enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-441 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-441 of SEQ ID NO: 2. In still other aspects of this embodiment, a BoNT/B enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-441 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-441 of SEQ ID NO: 2.

In another embodiment, a Clostridial toxin enzymatic domain comprises a BoNT/C1 enzymatic domain. In an aspect of this embodiment, a BoNT/C1 enzymatic domain comprises amino acids 1-449 of SEQ ID NO: 3. In another aspect of this embodiment, a BoNT/C1 enzymatic domain comprises a naturally occurring BoNT/C1 enzymatic domain variant, such as, e.g., a enzymatic domain from a BoNT/C1 isoform or a enzymatic domain from a BoNT/C1 subtype. In another aspect of this embodiment, a BoNT/C1 enzymatic domain comprises amino acids 1-449 of a naturally occurring BoNT/C1 enzymatic domain variant of SEQ ID NO: 3, such as, e.g., amino acids 1-449 of a BoNT/C1 isoform of SEQ ID NO: 3 or amino acids 1-449 of a BoNT/C1 subtype of SEQ ID NO: 3. In still another aspect of this embodiment, a BoNT/C1 enzymatic domain comprises a non-naturally occurring BoNT/C1 enzymatic domain variant, such as, e.g., a conservative BoNT/C1 enzymatic domain variant, a non-conservative BoNT/C1 enzymatic domain variant, a BoNT/C1 chimeric enzymatic domain, an active BoNT/C1 enzymatic domain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/C1 enzymatic domain comprises amino acids 1-449 of a non-naturally occurring BoNT/C1 enzymatic domain variant of SEQ ID NO: 3, such as, e.g., amino acids 1-449 of a conservative BoNT/C1 enzymatic domain variant of SEQ ID NO: 3, amino acids 1-449 of a non-conservative BoNT/C1 enzymatic domain variant of SEQ ID NO: 3, amino acids 1-449 of an active BoNT/C1 enzymatic domain fragment of SEQ ID NO: 3, or any combination thereof.

In other aspects of this embodiment, a BoNT/C1 enzymatic domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1-449 of SEQ ID NO: 3, at least 75% amino acid identity with amino acids 1-449 of SEQ ID NO: 3, at least 80% amino acid identity with amino acids 1-449 of SEQ ID NO: 3, at least 85% amino acid identity with amino acids 1-449 of SEQ ID NO: 3, at least 90% amino acid identity with amino acids 1-449 of SEQ ID NO: 3 or at least 95% amino acid identity with amino acids 1-449 of SEQ ID NO: 3. In yet other aspects of this embodiment, a BoNT/C1 enzymatic domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1-449 of SEQ ID NO: 3, at most 75% amino acid identity with amino acids 1-449 of SEQ ID NO: 3, at most 80% amino acid identity with amino acids 1-449 of SEQ ID NO: 3, at most 85% amino acid identity with amino acids 1-449 of SEQ ID NO: 3, at most 90% amino acid identity with amino acids 1-449 of SEQ ID NO: 3 or at most 95% amino acid identity with amino acids 1-449 of SEQ ID NO: 3.

In other aspects of this embodiment, a BoNT/C1 enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 1-449 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 1-449 of SEQ ID NO: 3. In yet other aspects of this embodiment, a BoNT/C1 enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-449 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-449 of SEQ ID NO: 3. In still other aspects of this embodiment, a BoNT/C1 enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-449 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-449 of SEQ ID NO: 3.

In other aspects of this embodiment, a BoNT/C1 enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-449 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-449 of SEQ ID NO: 3. In yet other aspects of this embodiment, a BoNT/C1 enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-449 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-449 of SEQ ID NO: 3. In still other aspects of this embodiment, a BoNT/C1 enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-449 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-449 of SEQ ID NO: 3.

In another embodiment, a Clostridial toxin enzymatic domain comprises a BoNT/D enzymatic domain. In an aspect of this embodiment, a BoNT/D enzymatic domain comprises amino acids 1-445 of SEQ ID NO: 4. In another aspect of this embodiment, a BoNT/D enzymatic domain comprises a naturally occurring BoNT/D enzymatic domain variant, such as, e.g., a enzymatic domain from a BoNT/D isoform or a enzymatic domain from a BoNT/D subtype. In another aspect of this embodiment, a BoNT/D enzymatic domain comprises amino acids 1-445 of a naturally occurring BoNT/D enzymatic domain variant of SEQ ID NO: 4, such as, e.g., amino acids 1-445 of a BoNT/D isoform of SEQ ID NO: 4 or amino acids 1-445 of a BoNT/D subtype of SEQ ID NO: 4. In still another aspect of this embodiment, a BoNT/D enzymatic domain comprises a non-naturally occurring BoNT/D enzymatic domain variant, such as, e.g., a conservative BoNT/D enzymatic domain variant, a non-conservative BoNT/D enzymatic domain variant, a BoNT/D chimeric enzymatic domain, an active BoNT/D enzymatic domain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/D enzymatic domain comprises amino acids 1-445 of a non-naturally occurring BoNT/D enzymatic domain variant of SEQ ID NO: 4, such as, e.g., amino acids 1-445 of a conservative BoNT/D enzymatic domain variant of SEQ ID NO: 4, amino acids 1-445 of a non-conservative BoNT/D enzymatic domain variant of SEQ ID NO: 4, amino acids 1-445 of an active BoNT/D enzymatic domain fragment of SEQ ID NO: 4, or any combination thereof.

In other aspects of this embodiment, a BoNT/D enzymatic domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1-445 of SEQ ID NO: 4, at least 75% amino acid identity with amino acids 1-445 of SEQ ID NO: 4, at least 80% amino acid identity with amino acids 1-445 of SEQ ID NO: 4, at least 85% amino acid identity with amino acids 1-445 of SEQ ID NO: 4, at least 90% amino acid identity with amino acids 1-445 of SEQ ID NO: 4 or at least 95% amino acid identity with amino acids 1-445 of SEQ ID NO: 4. In yet other aspects of this embodiment, a BoNT/D enzymatic domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1-445 of SEQ ID NO: 4, at most 75% amino acid identity with amino acids 1-445 of SEQ ID NO: 4, at most 80% amino acid identity with amino acids 1-445 of SEQ ID NO: 4, at most 85% amino acid identity with amino acids 1-445 of SEQ ID NO: 4, at most 90% amino acid identity with amino acids 1-445 of SEQ ID NO: 4 or at most 95% amino acid identity with amino acids 1-445 of SEQ ID NO: 4.

In other aspects of this embodiment, a BoNT/D enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 1-445 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 1-445 of SEQ ID NO: 4. In yet other aspects of this embodiment, a BoNT/D enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-445 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-445 of SEQ ID NO: 4. In still other aspects of this embodiment, a BoNT/D enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-445 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-445 of SEQ ID NO: 4.

In other aspects of this embodiment, a BoNT/D enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-445 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-445 of SEQ ID NO: 4. In yet other aspects of this embodiment, a BoNT/D enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-445 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-445 of SEQ ID NO: 4. In still other aspects of this embodiment, a BoNT/D enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-445 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-445 of SEQ ID NO: 4.

In another embodiment, a Clostridial toxin enzymatic domain comprises a BoNT/E enzymatic domain. In an aspect of this embodiment, a BoNT/E enzymatic domain comprises amino acids 1-422 of SEQ ID NO: 5. In another aspect of this embodiment, a BoNT/E enzymatic domain comprises a naturally occurring BoNT/E enzymatic domain variant, such as, e.g., a enzymatic domain from a BoNT/E isoform or a enzymatic domain from a BoNT/E subtype. In another aspect of this embodiment, a BoNT/E enzymatic domain comprises amino acids 1-422 of a naturally occurring BoNT/E enzymatic domain variant of SEQ ID NO: 5, such as, e.g., amino acids 1-422 of a BoNT/E isoform of SEQ ID NO: 5 or amino acids 1-422 of a BoNT/E subtype of SEQ ID NO: 5. In still another aspect of this embodiment, a BoNT/E enzymatic domain comprises a non-naturally occurring BoNT/E enzymatic domain variant, such as, e.g., a conservative BoNT/E enzymatic domain variant, a non-conservative BoNT/E enzymatic domain variant, a BoNT/E chimeric enzymatic domain, an active BoNT/E enzymatic domain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/E enzymatic domain comprises amino acids 1-422 of a non-naturally occurring BoNT/E enzymatic domain variant of SEQ ID NO: 5, such as, e.g., amino acids 1-422 of a conservative BoNT/E enzymatic domain variant of SEQ ID NO: 5, amino acids 1-422 of a non-conservative BoNT/E enzymatic domain variant of SEQ ID NO: 5, amino acids 1-422 of an active BoNT/E enzymatic domain fragment of SEQ ID NO: 5, or any combination thereof.

In other aspects of this embodiment, a BoNT/E enzymatic domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1-422 of SEQ ID NO: 5, at least 75% amino acid identity with amino acids 1-422 of SEQ ID NO: 5, at least 80% amino acid identity with amino acids 1-422 of SEQ ID NO: 5, at least 85% amino acid identity with amino acids 1-422 of SEQ ID NO: 5, at least 90% amino acid identity with amino acids 1-422 of SEQ ID NO: 5 or at least 95% amino acid identity with amino acids 1-422 of SEQ ID NO: 5. In yet other aspects of this embodiment, a BoNT/E enzymatic domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1-422 of SEQ ID NO: 5, at most 75% amino acid identity with amino acids 1-422 of SEQ ID NO: 5, at most 80% amino acid identity with amino acids 1-422 of SEQ ID NO: 5, at most 85% amino acid identity with amino acids 1-422 of SEQ ID NO: 5, at most 90% amino acid identity with amino acids 1-422 of SEQ ID NO: 5 or at most 95% amino acid identity with amino acids 1-422 of SEQ ID NO: 5.

In other aspects of this embodiment, a BoNT/E enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 1-422 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 1-422 of SEQ ID NO: 5. In yet other aspects of this embodiment, a BoNT/E enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-422 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-422 of SEQ ID NO: 5. In still other aspects of this embodiment, a BoNT/E enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-422 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-422 of SEQ ID NO: 5.

In other aspects of this embodiment, a BoNT/E enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-422 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-422 of SEQ ID NO: 5. In yet other aspects of this embodiment, a BoNT/E enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-422 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-422 of SEQ ID NO: 5. In still other aspects of this embodiment, a BoNT/E enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-422 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-422 of SEQ ID NO: 5.

In another embodiment, a Clostridial toxin enzymatic domain comprises a BoNT/F enzymatic domain. In an aspect of this embodiment, a BoNT/F enzymatic domain comprises amino acids 1-439 of SEQ ID NO: 6. In another aspect of this embodiment, a BoNT/F enzymatic domain comprises a naturally occurring BoNT/F enzymatic domain variant, such as, e.g., a enzymatic domain from a BoNT/F isoform or a enzymatic domain from a BoNT/F subtype. In another aspect of this embodiment, a BoNT/F enzymatic domain comprises amino acids 1-439 of a naturally occurring BoNT/F enzymatic domain variant of SEQ ID NO: 6, such as, e.g., amino acids 1-439 of a BoNT/F isoform of SEQ ID NO: 6 or amino acids 1-439 of a BoNT/F subtype of SEQ ID NO: 6. In still another aspect of this embodiment, a BoNT/F enzymatic domain comprises a non-naturally occurring BoNT/F enzymatic domain variant, such as, e.g., a conservative BoNT/F enzymatic domain variant, a non-conservative BoNT/F enzymatic domain variant, a BoNT/F chimeric enzymatic domain, an active BoNT/F enzymatic domain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/F enzymatic domain comprises amino acids 1-439 of a non-naturally occurring BoNT/F enzymatic domain variant of SEQ ID NO: 6, such as, e.g., amino acids 1-439 of a conservative BoNT/F enzymatic domain variant of SEQ ID NO: 6, amino acids 1-439 of a non-conservative BoNT/F enzymatic domain variant of SEQ ID NO: 6, amino acids 1-439 of an active BoNT/F enzymatic domain fragment of SEQ ID NO: 6, or any combination thereof.

In other aspects of this embodiment, a BoNT/F enzymatic domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1-439 of SEQ ID NO: 6, at least 75% amino acid identity with amino acids 1-439 of SEQ ID NO: 6, at least 80% amino acid identity with amino acids 1-439 of SEQ ID NO: 6, at least 85% amino acid identity with amino acids 1-439 of SEQ ID NO: 6, at least 90% amino acid identity with amino acids 1-439 of SEQ ID NO: 6 or at least 95% amino acid identity with amino acids 1-439 of SEQ ID NO: 6. In yet other aspects of this embodiment, a BoNT/F enzymatic domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1-439 of SEQ ID NO: 6, at most 75% amino acid identity with amino acids 1-439 of SEQ ID NO: 6, at most 80% amino acid identity with amino acids 1-439 of SEQ ID NO: 6, at most 85% amino acid identity with amino acids 1-439 of SEQ ID NO: 6, at most 90% amino acid identity with amino acids 1-439 of SEQ ID NO: 6 or at most 95% amino acid identity with amino acids 1-439 of SEQ ID NO: 6.

In other aspects of this embodiment, a BoNT/F enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 1-439 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 1-439 of SEQ ID NO: 6. In yet other aspects of this embodiment, a BoNT/F enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-439 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-439 of SEQ ID NO: 6. In still other aspects of this embodiment, a BoNT/F enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-439 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-439 of SEQ ID NO: 6.

In other aspects of this embodiment, a BoNT/F enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-439 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-439 of SEQ ID NO: 6. In yet other aspects of this embodiment, a BoNT/F enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-439 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-439 of SEQ ID NO: 6. In still other aspects of this embodiment, a BoNT/F enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-439 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-439 of SEQ ID NO: 6.

In another embodiment, a Clostridial toxin enzymatic domain comprises a BoNT/G enzymatic domain. In an aspect of this embodiment, a BoNT/G enzymatic domain comprises amino acids 1-446 of SEQ ID NO: 7. In another aspect of this embodiment, a BoNT/G enzymatic domain comprises a naturally occurring BoNT/G enzymatic domain variant, such as, e.g., a enzymatic domain from a BoNT/G isoform or a enzymatic domain from a BoNT/G subtype. In another aspect of this embodiment, a BoNT/G enzymatic domain comprises amino acids 1-446 of a naturally occurring BoNT/G enzymatic domain variant of SEQ ID NO: 7, such as, e.g., amino acids 1-446 of a BoNT/G isoform of SEQ ID NO: 7 or amino acids 1-446 of a BoNT/G subtype of SEQ ID NO: 7. In still another aspect of this embodiment, a BoNT/G enzymatic domain comprises a non-naturally occurring BoNT/G enzymatic domain variant, such as, e.g., a conservative BoNT/G enzymatic domain variant, a non-conservative BoNT/G enzymatic domain variant, a BoNT/G chimeric enzymatic domain, an active BoNT/G enzymatic domain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/G enzymatic domain comprises amino acids 1-446 of a non-naturally occurring BoNT/G enzymatic domain variant of SEQ ID NO: 7, such as, e.g., amino acids 1-446 of a conservative BoNT/G enzymatic domain variant of SEQ ID NO: 7, amino acids 1-446 of a non-conservative BoNT/G enzymatic domain variant of SEQ ID NO: 7, amino acids 1-446 of an active BoNT/G enzymatic domain fragment of SEQ ID NO: 7, or any combination thereof.

In other aspects of this embodiment, a BoNT/G enzymatic domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1-446 of SEQ ID NO: 7, at least 75% amino acid identity with amino acids 1-446 of SEQ ID NO: 7, at least 80% amino acid identity with amino acids 1-446 of SEQ ID NO: 7, at least 85% amino acid identity with amino acids 1-446 of SEQ ID NO: 7, at least 90% amino acid identity with amino acids 1-446 of SEQ ID NO: 7 or at least 95% amino acid identity with amino acids 1-446 of SEQ ID NO: 7. In yet other aspects of this embodiment, a BoNT/G enzymatic domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1-446 of SEQ ID NO: 7, at most 75% amino acid identity with amino acids 1-446 of SEQ ID NO: 7, at most 80% amino acid identity with amino acids 1-446 of SEQ ID NO: 7, at most 85% amino acid identity with amino acids 1-446 of SEQ ID NO: 7, at most 90% amino acid identity with amino acids 1-446 of SEQ ID NO: 7 or at most 95% amino acid identity with amino acids 1-446 of SEQ ID NO: 7.

In other aspects of this embodiment, a BoNT/G enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 1-446 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 1-446 of SEQ ID NO: 7. In yet other aspects of this embodiment, a BoNT/G enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-446 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-446 of SEQ ID NO: 7. In still other aspects of this embodiment, a BoNT/G enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-446 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-446 of SEQ ID NO: 7.

In other aspects of this embodiment, a BoNT/G enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-446 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-446 of SEQ ID NO: 7. In yet other aspects of this embodiment, a BoNT/G enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-446 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-446 of SEQ ID NO: 7. In still other aspects of this embodiment, a BoNT/G enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-446 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-446 of SEQ ID NO: 7.

In another embodiment, a Clostridial toxin enzymatic domain comprises a TeNT enzymatic domain. In an aspect of this embodiment, a TeNT enzymatic domain comprises amino acids 1-457 of SEQ ID NO: 8. In another aspect of this embodiment, a TeNT enzymatic domain comprises a naturally occurring TeNT enzymatic domain variant, such as, e.g., a enzymatic domain from a TeNT isoform or a enzymatic domain from a TeNT subtype. In another aspect of this embodiment, a TeNT enzymatic domain comprises amino acids 1-457 of a naturally occurring TeNT enzymatic domain variant of SEQ ID NO: 8, such as, e.g., amino acids 1-457 of a TeNT isoform of SEQ ID NO: 8 or amino acids 1-457 of a TeNT subtype of SEQ ID NO: 8. In still another aspect of this embodiment, a TeNT enzymatic domain comprises a non-naturally occurring TeNT enzymatic domain variant, such as, e.g., a conservative TeNT enzymatic domain variant, a non-conservative TeNT enzymatic domain variant, a TeNT chimeric enzymatic domain, an active TeNT enzymatic domain fragment, or any combination thereof. In still another aspect of this embodiment, a TeNT enzymatic domain comprises amino acids 1-457 of a non-naturally occurring TeNT enzymatic domain variant of SEQ ID NO: 8, such as, e.g., amino acids 1-457 of a conservative TeNT enzymatic domain variant of SEQ ID NO: 8, amino acids 1-457 of a non-conservative TeNT enzymatic domain variant of SEQ ID NO: 8, amino acids 1-457 of an active TeNT enzymatic domain fragment of SEQ ID NO: 8, or any combination thereof.

In other aspects of this embodiment, a TeNT enzymatic domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1-457 of SEQ ID NO: 8, at least 75% amino acid identity with amino acids 1-457 of SEQ ID NO: 8, at least 80% amino acid identity with amino acids 1-457 of SEQ ID NO: 8, at least 85% amino acid identity with amino acids 1-457 of SEQ ID NO: 8, at least 90% amino acid identity with amino acids 1-457 of SEQ ID NO: 8 or at least 95% amino acid identity with amino acids 1-457 of SEQ ID NO: 8. In yet other aspects of this embodiment, a TeNT enzymatic domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1-457 of SEQ ID NO: 8, at most 75% amino acid identity with amino acids 1-457 of SEQ ID NO: 8, at most 80% amino acid identity with amino acids 1-457 of SEQ ID NO: 8, at most 85% amino acid identity with amino acids 1-457 of SEQ ID NO: 8, at most 90% amino acid identity with amino acids 1-457 of SEQ ID NO: 8 or at most 95% amino acid identity with amino acids 1-457 of SEQ ID NO: 8.

In other aspects of this embodiment, a TeNT enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 1-457 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 1-457 of SEQ ID NO: 8. In yet other aspects of this embodiment, a TeNT enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-457 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-457 of SEQ ID NO: 8. In still other aspects of this embodiment, a TeNT enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-457 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-457 of SEQ ID NO: 8.

In other aspects of this embodiment, a TeNT enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-457 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-457 of SEQ ID NO: 8. In yet other aspects of this embodiment, a TeNT enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-457 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-457 of SEQ ID NO: 8. In still other aspects of this embodiment, a TeNT enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-457 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-457 of SEQ ID NO: 8.

In another embodiment, a Clostridial toxin enzymatic domain comprises a BaNT enzymatic domain. In an aspect of this embodiment, a BaNT enzymatic domain comprises amino acids 1-431 of SEQ ID NO: 9. In another aspect of this embodiment, a BaNT enzymatic domain comprises a naturally occurring BaNT enzymatic domain variant, such as, e.g., a enzymatic domain from a BaNT isoform or a enzymatic domain from a BaNT subtype. In another aspect of this embodiment, a BaNT enzymatic domain comprises amino acids 1-431 of a naturally occurring BaNT enzymatic domain variant of SEQ ID NO: 9, such as, e.g., amino acids 1-431 of a BaNT isoform of SEQ ID NO: 9 or amino acids 1-431 of a BaNT subtype of SEQ ID NO: 9. In still another aspect of this embodiment, a BaNT enzymatic domain comprises a non-naturally occurring BaNT enzymatic domain variant, such as, e.g., a conservative BaNT enzymatic domain variant, a non-conservative BaNT enzymatic domain variant, a BaNT chimeric enzymatic domain, an active BaNT enzymatic domain fragment, or any combination thereof. In still another aspect of this embodiment, a BaNT enzymatic domain comprises amino acids 1-431 of a non-naturally occurring BaNT enzymatic domain variant of SEQ ID NO: 9, such as, e.g., amino acids 1-431 of a conservative BaNT enzymatic domain variant of SEQ ID NO: 9, amino acids 1-431 of a non-conservative BaNT enzymatic domain variant of SEQ ID NO: 9, amino acids 1-431 of an active BaNT enzymatic domain fragment of SEQ ID NO: 9, or any combination thereof.

In other aspects of this embodiment, a BaNT enzymatic domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1-431 of SEQ ID NO: 9, at least 75% amino acid identity with amino acids 1-431 of SEQ ID NO: 9, at least 80% amino acid identity with amino acids 1-431 of SEQ ID NO: 9, at least 85% amino acid identity with amino acids 1-431 of SEQ ID NO: 9, at least 90% amino acid identity with amino acids 1-431 of SEQ ID NO: 9 or at least 95% amino acid identity with amino acids 1-431 of SEQ ID NO: 9. In yet other aspects of this embodiment, a BaNT enzymatic domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1-431 of SEQ ID NO: 9, at most 75% amino acid identity with amino acids 1-431 of SEQ ID NO: 9, at most 80% amino acid identity with amino acids 1-431 of SEQ ID NO: 9, at most 85% amino acid identity with amino acids 1-431 of SEQ ID NO: 9, at most 90% amino acid identity with amino acids 1-431 of SEQ ID NO: 9 or at most 95% amino acid identity with amino acids 1-431 of SEQ ID NO: 9.

In other aspects of this embodiment, a BaNT enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 1-431 of SEQ ID NO: 9. In other aspects of this embodiment, a BaNT enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 1-431 of SEQ ID NO: 9. In yet other aspects of this embodiment, a BaNT enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-431 of SEQ ID NO: 9. In other aspects of this embodiment, a BaNT enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-431 of SEQ ID NO: 9. In still other aspects of this embodiment, a BaNT enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-431 of SEQ ID NO: 9. In other aspects of this embodiment, a BaNT enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-431 of SEQ ID NO: 9.

In other aspects of this embodiment, a BaNT enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-431 of SEQ ID NO: 9. In other aspects of this embodiment, a BaNT enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-431 of SEQ ID NO: 9. In yet other aspects of this embodiment, a BaNT enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-431 of SEQ ID NO: 9. In other aspects of this embodiment, a BaNT enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-431 of SEQ ID NO: 9. In still other aspects of this embodiment, a BaNT enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-431 of SEQ ID NO: 9. In other aspects of this embodiment, a BaNT enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-431 of SEQ ID NO: 9.

In another embodiment, a Clostridial toxin enzymatic domain comprises a BuNT enzymatic domain. In an aspect of this embodiment, a BuNT enzymatic domain comprises amino acids 1-422 of SEQ ID NO: 10. In another aspect of this embodiment, a BuNT enzymatic domain comprises a naturally occurring BuNT enzymatic domain variant, such as, e.g., a enzymatic domain from a BuNT isoform or a enzymatic domain from a BuNT subtype. In another aspect of this embodiment, a BuNT enzymatic domain comprises amino acids 1-422 of a naturally occurring BuNT enzymatic domain variant of SEQ ID NO: 10, such as, e.g., amino acids 1-422 of a BuNT isoform of SEQ ID NO: 10 or amino acids 1-422 of a BuNT subtype of SEQ ID NO: 10. In still another aspect of this embodiment, a BuNT enzymatic domain comprises a non-naturally occurring BuNT enzymatic domain variant, such as, e.g., a conservative BuNT enzymatic domain variant, a non-conservative BuNT enzymatic domain variant, a BuNT chimeric enzymatic domain, an active BuNT enzymatic domain fragment, or any combination thereof. In still another aspect of this embodiment, a BuNT enzymatic domain comprises amino acids 1-422 of a non-naturally occurring BuNT enzymatic domain variant of SEQ ID NO: 10, such as, e.g., amino acids 1-422 of a conservative BuNT enzymatic domain variant of SEQ ID NO: 10, amino acids 1-422 of a non-conservative BuNT enzymatic domain variant of SEQ ID NO: 10, amino acids 1-422 of an active BuNT enzymatic domain fragment of SEQ ID NO: 10, or any combination thereof.

In other aspects of this embodiment, a BuNT enzymatic domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 1-422 of SEQ ID NO: 10, at least 75% amino acid identity with amino acids 1-422 of SEQ ID NO: 10, at least 80% amino acid identity with amino acids 1-422 of SEQ ID NO: 10, at least 85% amino acid identity with amino acids 1-422 of SEQ ID NO: 10, at least 90% amino acid identity with amino acids 1-422 of SEQ ID NO: 10 or at least 95% amino acid identity with amino acids 1-422 of SEQ ID NO: 10. In yet other aspects of this embodiment, a BuNT enzymatic domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 1-422 of SEQ ID NO: 10, at most 75% amino acid identity with amino acids 1-422 of SEQ ID NO: 10, at most 80% amino acid identity with amino acids 1-422 of SEQ ID NO: 10, at most 85% amino acid identity with amino acids 1-422 of SEQ ID NO: 10, at most 90% amino acid identity with amino acids 1-422 of SEQ ID NO: 10 or at most 95% amino acid identity with amino acids 1-422 of SEQ ID NO: 10.

In other aspects of this embodiment, a BuNT enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 1-422 of SEQ ID NO: 10. In other aspects of this embodiment, a BuNT enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 1-422 of SEQ ID NO: 10. In yet other aspects of this embodiment, a BuNT enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-422 of SEQ ID NO: 10. In other aspects of this embodiment, a BuNT enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 1-422 of SEQ ID NO: 10. In still other aspects of this embodiment, a BuNT enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-422 of SEQ ID NO: 10. In other aspects of this embodiment, a BuNT enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 1-422 of SEQ ID NO: 10.

In other aspects of this embodiment, a BuNT enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-422 of SEQ ID NO: 10. In other aspects of this embodiment, a BuNT enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 1-422 of SEQ ID NO: 10. In yet other aspects of this embodiment, a BuNT enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-422 of SEQ ID NO: 10. In other aspects of this embodiment, a BuNT enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 1-422 of SEQ ID NO: 10. In still other aspects of this embodiment, a BuNT enzymatic domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-422 of SEQ ID NO: 10. In other aspects of this embodiment, a BuNT enzymatic domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 1-422 of SEQ ID NO: 10.

The “translocation element” comprises a portion of a clostridial neurotoxin heavy chain having a translocation activity. By “translocation” is meant the ability to facilitate the transport of a polypeptide through a vesicular membrane, thereby exposing some or all of the polypeptide to the cytoplasm. In the various botulinum neurotoxins translocation is thought to involve an allosteric conformational change of the heavy chain caused by a decrease in pH within the endosome. This conformational change appears to involve and be mediated by the N terminal half of the heavy chain and to result in the formation of pores in the vesicular membrane; this change permits the movement of the proteolytic light chain from within the endosomal vesicle into the cytoplasm. See e.g., Lacy, et al., Nature Struct. Biol. 5:898-902 (October 1998).

The amino acid sequence of the translocation-mediating portion of the botulinum neurotoxin heavy chain is known to those of skill in the art; additionally, those amino acid residues within this portion that are known to be essential for conferring the translocation activity are also known. It would therefore be well within the ability of one of ordinary skill in the art, for example, to employ the naturally occurring N-terminal peptide half of the heavy chain of any of the various Clostridium tetanus or Clostridium botulinum neurotoxin subtypes as a translocation element, or to design an analogous translocation element by aligning the primary sequences of the N-terminal halves of the various heavy chains and selecting a consensus primary translocation sequence based on conserved amino acid, polarity, steric and hydrophobicity characteristics between the sequences.

Aspects of the present invention provide, in part, a Clostridial toxin translocation domain. As used herein, the term “Clostridial toxin translocation domain” means any Clostridial toxin polypeptide that can execute the translocation step of the intoxication process that mediates Clostridial toxin light chain translocation. Thus, a Clostridial toxin translocation domain facilitates the movement of a Clostridial toxin light chain across a membrane and encompasses the movement of a Clostridial toxin light chain through the membrane an intracellular vesicle into the cytoplasm of a cell. Non-limiting examples of a Clostridial toxin translocation domain include, e.g., a BoNT/A translocation domain, a BoNT/B translocation domain, a BoNT/C1 translocation domain, a BoNT/D translocation domain, a BoNT/E translocation domain, a BoNT/F translocation domain, a BoNT/G translocation domain, a TeNT translocation domain, a BaNT translocation domain, and a BuNT translocation domain. Other non-limiting examples of a Clostridial toxin translocation domain include, e.g., amino acids 449-873 of SEQ ID NO: 1, amino acids 442-860 of SEQ ID NO: 2, amino acids 450-868 of SEQ ID NO: 3, amino acids 446-864 of SEQ ID NO: 4, amino acids 423-847 of SEQ ID NO: 5, amino acids 440-866 of SEQ ID NO: 6, amino acids 447-865 of SEQ ID NO: 7, amino acids 458-881 of SEQ ID NO: 8, amino acids 432-857 of SEQ ID NO: 9, and amino acids 423-847 of SEQ ID NO: 10.

A Clostridial toxin translocation domain includes, without limitation, naturally occurring Clostridial toxin translocation domain variants, such as, e.g., Clostridial toxin translocation domain isoforms and Clostridial toxin translocation domain subtypes; non-naturally occurring Clostridial toxin translocation domain variants, such as, e.g., conservative Clostridial toxin translocation domain variants, non-conservative Clostridial toxin translocation domain variants, Clostridial toxin translocation domain chimerics, active Clostridial toxin translocation domain fragments thereof, or any combination thereof.

As used herein, the term “Clostridial toxin translocation domain variant,” whether naturally-occurring or non-naturally-occurring, means a Clostridial toxin translocation domain that has at least one amino acid change from the corresponding region of the disclosed reference sequences (Table 1) and can be described in percent identity to the corresponding region of that reference sequence. Unless expressly indicated, all Clostridial toxin translocation domain variants disclosed in the present specification are capable of executing the translocation step of the intoxication process that mediates Clostridial toxin light chain translocation. As non-limiting examples, a BoNT/A translocation domain variant comprising amino acids 449-873 of SEQ ID NO: 1 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 449-873 of SEQ ID NO: 1; a BoNT/B translocation domain variant comprising amino acids 442-860 of SEQ ID NO: 2 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 442-860 of SEQ ID NO: 2; a BoNT/C1 translocation domain variant comprising amino acids 450-868 of SEQ ID NO: 3 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 450-868 of SEQ ID NO: 3; a BoNT/D translocation domain variant comprising amino acids 446-864 of SEQ ID NO: 4 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 446-864 of SEQ ID NO: 4; a BoNT/E translocation domain variant comprising amino acids 423-847 of SEQ ID NO: 5 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 423-847 of SEQ ID NO: 5; a BoNT/F translocation domain variant comprising amino acids 440-866 of SEQ ID NO: 6 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 440-866 of SEQ ID NO: 6; a BoNT/G translocation domain variant comprising amino acids 447-865 of SEQ ID NO: 7 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 447-865 of SEQ ID NO: 7; a TeNT translocation domain variant comprising amino acids 458-881 of SEQ ID NO: 8 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 458-881 of SEQ ID NO: 8; a BaNT translocation domain variant comprising amino acids 432-857 of SEQ ID NO: 9 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 432-857 of SEQ ID NO: 9; and a BuNT translocation domain variant comprising amino acids 423-847 of SEQ ID NO: 10 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 423-847 of SEQ ID NO: 10.

It is recognized by those of skill in the art that within each serotype of Clostridial toxin there can be naturally occurring Clostridial toxin translocation domain variants that differ somewhat in their amino acid sequence, and also in the nucleic acids encoding these proteins. For example, there are presently four BoNT/A subtypes, BoNT/A1, BoNT/A2, BoNT/A3 and BoNT/A4, with specific translocation domain subtypes showing approximately 87% amino acid identity when compared to another BoNT/A translocation domain subtype. As used herein, the term “naturally occurring Clostridial toxin translocation domain variant” means any Clostridial toxin translocation domain produced by a naturally-occurring process, including, without limitation, Clostridial toxin translocation domain isoforms produced from alternatively-spliced transcripts, Clostridial toxin translocation domain isoforms produced by spontaneous mutation and Clostridial toxin translocation domain subtypes. A naturally occurring Clostridial toxin translocation domain variant can function in substantially the same manner as the reference Clostridial toxin translocation domain on which the naturally occurring Clostridial toxin translocation domain variant is based, and can be substituted for the reference Clostridial toxin translocation domain in any aspect of the present invention. A naturally occurring Clostridial toxin translocation domain variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids or 100 or more amino acids from the reference Clostridial toxin translocation domain on which the naturally occurring Clostridial toxin translocation domain variant is based. A naturally occurring Clostridial toxin translocation domain variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin translocation domain on which the naturally occurring Clostridial toxin translocation domain variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin translocation domain on which the naturally occurring Clostridial toxin translocation domain variant is based.

A non-limiting examples of a naturally occurring Clostridial toxin translocation domain variant is a Clostridial toxin translocation domain isoform such as, e.g., a BoNT/A translocation domain isoform, a BoNT/B translocation domain isoform, a BoNT/C1 translocation domain isoform, a BoNT/D translocation domain isoform, a BoNT/E translocation domain isoform, a BoNT/F translocation domain isoform, a BoNT/G translocation domain isoform, a TeNT translocation domain isoform, a BaNT translocation domain isoform, and a BuNT translocation domain isoform. A Clostridial toxin translocation domain isoform can function in substantially the same manner as the reference Clostridial toxin translocation domain on which the Clostridial toxin translocation domain isoform is based, and can be substituted for the reference Clostridial toxin translocation domain in any aspect of the present invention.

Another non-limiting examples of a naturally occurring Clostridial toxin translocation domain variant is a Clostridial toxin translocation domain subtype such as, e.g., a translocation domain from subtype BoNT/A1, BoNT/A2, BoNT/A3 and BoNT/A4; a translocation domain from subtype BoNT/B1, BoNT/B2, BoNT/B bivalent and BoNT/B nonproteolytic; a translocation domain from subtype BoNT/C1-1 and BoNT/C1-2; a translocation domain from subtype BoNT/E1, BoNT/E2 and BoNT/E3; and a translocation domain from subtype BoNT/F1, BoNT/F2, BoNT/F3 and BoNT/F4. A Clostridial toxin translocation domain subtype can function in substantially the same manner as the reference Clostridial toxin translocation domain on which the Clostridial toxin translocation domain subtype is based, and can be substituted for the reference Clostridial toxin translocation domain in any aspect of the present invention.

As used herein, the term “non-naturally occurring Clostridial toxin translocation domain variant” means any Clostridial toxin translocation domain produced with the aid of human manipulation, including, without limitation, Clostridial toxin translocation domains produced by genetic engineering using random mutagenesis or rational design and Clostridial toxin translocation domains produced by chemical synthesis. Non-limiting examples of non-naturally occurring Clostridial toxin translocation domain variants include, e.g., conservative Clostridial toxin translocation domain variants, non-conservative Clostridial toxin translocation domain variants, Clostridial toxin translocation domain chimeric variants and active Clostridial toxin translocation domain fragments.

As used herein, the term “conservative Clostridial toxin translocation domain variant” means a Clostridial toxin translocation domain that has at least one amino acid substituted by another amino acid or an amino acid analog that has at least one property similar to that of the original amino acid from the reference Clostridial toxin translocation domain sequence (Table 1). Examples of properties include, without limitation, similar size, topography, charge, hydrophobicity, hydrophilicity, lipophilicity, covalent-bonding capacity, hydrogen-bonding capacity, a physicochemical property, of the like, or any combination thereof. A conservative Clostridial toxin translocation domain variant can function in substantially the same manner as the reference Clostridial toxin translocation domain on which the conservative Clostridial toxin translocation domain variant is based, and can be substituted for the reference Clostridial toxin translocation domain in any aspect of the present invention. A conservative Clostridial toxin translocation domain variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids, 100 or more amino acids, 200 or more amino acids, 300 or more amino acids, 400 or more amino acids, or 500 or more amino acids from the reference Clostridial toxin translocation domain on which the conservative Clostridial toxin translocation domain variant is based. A conservative Clostridial toxin translocation domain variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin translocation domain on which the conservative Clostridial toxin translocation domain variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin translocation domain on which the conservative Clostridial toxin translocation domain variant is based. Non-limiting examples of a conservative Clostridial toxin translocation domain variant include, e.g., conservative BoNT/A translocation domain variants, conservative BoNT/B translocation domain variants, conservative BoNT/C1 translocation domain variants, conservative BoNT/D translocation domain variants, conservative BoNT/E translocation domain variants, conservative BoNT/F translocation domain variants, conservative BoNT/G translocation domain variants, conservative TeNT translocation domain variants, conservative BaNT translocation domain variants, and conservative BuNT translocation domain variants.

As used herein, the term “non-conservative Clostridial toxin translocation domain variant” means a Clostridial toxin translocation domain in which 1) at least one amino acid is deleted from the reference Clostridial toxin translocation domain on which the non-conservative Clostridial toxin translocation domain variant is based; 2) at least one amino acid added to the reference Clostridial toxin translocation domain on which the non-conservative Clostridial toxin translocation domain is based; or 3) at least one amino acid is substituted by another amino acid or an amino acid analog that does not share any property similar to that of the original amino acid from the reference Clostridial toxin translocation domain sequence (Table 1). A non-conservative Clostridial toxin translocation domain variant can function in substantially the same manner as the reference Clostridial toxin translocation domain on which the non-conservative Clostridial toxin translocation domain variant is based, and can be substituted for the reference Clostridial toxin translocation domain in any aspect of the present invention. A non-conservative Clostridial toxin translocation domain variant can delete one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids from the reference Clostridial toxin translocation domain on which the non-conservative Clostridial toxin translocation domain variant is based. A non-conservative Clostridial toxin translocation domain variant can add one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids to the reference Clostridial toxin translocation domain on which the non-conservative Clostridial toxin translocation domain variant is based. A non-conservative Clostridial toxin translocation domain variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids, 100 or more amino acids, 200 or more amino acids, 300 or more amino acids, 400 or more amino acids, or 500 or more amino acids from the reference Clostridial toxin translocation domain on which the non-conservative Clostridial toxin translocation domain variant is based. A non-conservative Clostridial toxin translocation domain variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin translocation domain on which the non-conservative Clostridial toxin translocation domain variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin translocation domain on which the non-conservative Clostridial toxin translocation domain variant is based. Non-limiting examples of a non-conservative Clostridial toxin translocation domain variant include, e.g., non-conservative BoNT/A translocation domain variants, non-conservative BoNT/B translocation domain variants, non-conservative BoNT/C1 translocation domain variants, non-conservative BoNT/D translocation domain variants, non-conservative BoNT/E translocation domain variants, non-conservative BoNT/F translocation domain variants, non-conservative BoNT/G translocation domain variants, and non-conservative TeNT translocation domain variants, non-conservative BaNT translocation domain variants, and non-conservative BuNT translocation domain variants.

As used herein, the term “Clostridial toxin translocation domain chimeric” means a polypeptide comprising at least a portion of a Clostridial toxin translocation domain and at least a portion of at least one other polypeptide to form a toxin translocation domain with at least one property different from the reference Clostridial toxin translocation domains of Table 1, with the proviso that this Clostridial toxin translocation domain chimeric is still capable of specifically targeting the core components of the neurotransmitter release apparatus and thus participate in executing the overall cellular mechanism whereby a Clostridial toxin proteolytically cleaves a substrate.

As used herein, the term “active Clostridial toxin translocation domain fragment” means any of a variety of Clostridial toxin fragments comprising the translocation domain can be useful in aspects of the present invention with the proviso that these active fragments can facilitate the release of the LC from intracellular vesicles into the cytoplasm of the target cell and thus participate in executing the overall cellular mechanism whereby a Clostridial toxin proteolytically cleaves a substrate. The translocation domains from the heavy chains of Clostridial toxins are approximately 410-430 amino acids in length and comprise a translocation domain (Table 1). Research has shown that the entire length of a translocation domain from a Clostridial toxin heavy chain is not necessary for the translocating activity of the translocation domain. Thus, aspects of this embodiment can include Clostridial toxin translocation domains comprising a translocation domain having a length of, e.g., at least 350 amino acids, at least 375 amino acids, at least 400 amino acids and at least 425 amino acids. Other aspects of this embodiment can include Clostridial toxin translocation domains comprising translocation domain having a length of, e.g., at most 350 amino acids, at most 375 amino acids, at most 400 amino acids and at most 425 amino acids.

Any of a variety of sequence alignment methods can be used to determine percent identity of naturally-occurring Clostridial toxin translocation domain variants and non-naturally-occurring Clostridial toxin translocation domain variants, including, without limitation, global methods, local methods and hybrid methods, such as, e.g., segment approach methods. Protocols to determine percent identity are routine procedures within the scope of one skilled in the art and from the teaching herein.

Thus, in an embodiment, a modified Clostridial toxin disclosed in the present specification comprises a Clostridial toxin translocation domain. In an aspect of this embodiment, a Clostridial toxin translocation domain comprises a naturally occurring Clostridial toxin translocation domain variant, such as, e.g., a Clostridial toxin translocation domain isoform or a Clostridial toxin translocation domain subtype. In another aspect of this embodiment, a Clostridial toxin translocation domain comprises a non-naturally occurring Clostridial toxin translocation domain variant, such as, e.g., a conservative Clostridial toxin translocation domain variant, a non-conservative Clostridial toxin translocation domain variant, a Clostridial toxin chimeric translocation domain, an active Clostridial toxin translocation domain fragment, or any combination thereof.

In another embodiment, a Clostridial toxin translocation domain comprises a BoNT/A translocation domain. In an aspect of this embodiment, a BoNT/A translocation domain comprises amino acids 449-873 of SEQ ID NO: 1. In another aspect of this embodiment, a BoNT/A translocation domain comprises a naturally occurring BoNT/A translocation domain variant, such as, e.g., a translocation domain from a BoNT/A isoform or a translocation domain from a BoNT/A subtype. In another aspect of this embodiment, a BoNT/A translocation domain comprises amino acids 449-873 of a naturally occurring BoNT/A translocation domain variant of SEQ ID NO: 1, such as, e.g., amino acids 449-873 of a BoNT/A isoform of SEQ ID NO: 1 or amino acids 449-873 of a BoNT/A subtype of SEQ ID NO: 1. In still another aspect of this embodiment, a BoNT/A translocation domain comprises a non-naturally occurring BoNT/A translocation domain variant, such as, e.g., a conservative BoNT/A translocation domain variant, a non-conservative BoNT/A translocation domain variant, a BoNT/A chimeric translocation domain, an active BoNT/A translocation domain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/A translocation domain comprises amino acids 449-873 of a non-naturally occurring BoNT/A translocation domain variant of SEQ ID NO: 1, such as, e.g., amino acids 449-873 of a conservative BoNT/A translocation domain variant of SEQ ID NO: 1, amino acids 449-873 of a non-conservative BoNT/A translocation domain variant of SEQ ID NO: 1, amino acids 449-873 of an active BoNT/A translocation domain fragment of SEQ ID NO: 1, or any combination thereof.

In other aspects of this embodiment, a BoNT/A translocation domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 449-873 of SEQ ID NO: 1, at least 75% amino acid identity with amino acids 449-873 of SEQ ID NO: 1, at least 80% amino acid identity with amino acids 449-873 of SEQ ID NO: 1, at least 85% amino acid identity with amino acids 449-873 of SEQ ID NO: 1, at least 90% amino acid identity with amino acids 449-873 of SEQ ID NO: 1 or at least 95% amino acid identity with amino acids 449-873 of SEQ ID NO: 1. In yet other aspects of this embodiment, a BoNT/A translocation domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 449-873 of SEQ ID NO: 1, at most 75% amino acid identity with amino acids 449-873 of SEQ ID NO: 1, at most 80% amino acid identity with amino acids 449-873 of SEQ ID NO: 1, at most 85% amino acid identity with amino acids 449-873 of SEQ ID NO: 1, at most 90% amino acid identity with amino acids 449-873 of SEQ ID NO: 1 or at most 95% amino acid identity with amino acids 449-873 of SEQ ID NO: 1.

In other aspects of this embodiment, a BoNT/A translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 449-873 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 449-873 of SEQ ID NO: 1. In yet other aspects of this embodiment, a BoNT/A translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 449-873 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 449-873 of SEQ ID NO: 1. In still other aspects of this embodiment, a BoNT/A translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 449-873 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 449-873 of SEQ ID NO: 1.

In other aspects of this embodiment, a BoNT/A translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 449-873 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 449-873 of SEQ ID NO: 1. In yet other aspects of this embodiment, a BoNT/A translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 449-873 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 449-873 of SEQ ID NO: 1. In still other aspects of this embodiment, a BoNT/A translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 449-873 of SEQ ID NO: 1. In other aspects of this embodiment, a BoNT/A translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 449-873 of SEQ ID NO: 1.

In another embodiment, a Clostridial toxin translocation domain comprises a BoNT/B translocation domain. In an aspect of this embodiment, a BoNT/B translocation domain comprises amino acids 442-860 of SEQ ID NO: 2. In another aspect of this embodiment, a BoNT/B translocation domain comprises a naturally occurring BoNT/B translocation domain variant, such as, e.g., a translocation domain from a BoNT/B isoform or a translocation domain from a BoNT/B subtype. In another aspect of this embodiment, a BoNT/B translocation domain comprises amino acids 442-860 of a naturally occurring BoNT/B translocation domain variant of SEQ ID NO: 2, such as, e.g., amino acids 442-860 of a BoNT/B isoform of SEQ ID NO: 2 or amino acids 442-860 of a BoNT/B subtype of SEQ ID NO: 2. In still another aspect of this embodiment, a BoNT/B translocation domain comprises a non-naturally occurring BoNT/B translocation domain variant, such as, e.g., a conservative BoNT/B translocation domain variant, a non-conservative BoNT/B translocation domain variant, a BoNT/B chimeric translocation domain, an active BoNT/B translocation domain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/B translocation domain comprises amino acids 442-860 of a non-naturally occurring BoNT/B translocation domain variant of SEQ ID NO: 2, such as, e.g., amino acids 442-860 of a conservative BoNT/B translocation domain variant of SEQ ID NO: 2, amino acids 442-860 of a non-conservative BoNT/B translocation domain variant of SEQ ID NO: 2, amino acids 442-860 of an active BoNT/B translocation domain fragment of SEQ ID NO: 2, or any combination thereof.

In other aspects of this embodiment, a BoNT/B translocation domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 442-860 of SEQ ID NO: 2, at least 75% amino acid identity with amino acids 442-860 of SEQ ID NO: 2, at least 80% amino acid identity with amino acids 442-860 of SEQ ID NO: 2, at least 85% amino acid identity with amino acids 442-860 of SEQ ID NO: 2, at least 90% amino acid identity with amino acids 442-860 of SEQ ID NO: 2 or at least 95% amino acid identity with amino acids 442-860 of SEQ ID NO: 2. In yet other aspects of this embodiment, a BoNT/B translocation domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 442-860 of SEQ ID NO: 2, at most 75% amino acid identity with amino acids 442-860 of SEQ ID NO: 2, at most 80% amino acid identity with amino acids 442-860 of SEQ ID NO: 2, at most 85% amino acid identity with amino acids 442-860 of SEQ ID NO: 2, at most 90% amino acid identity with amino acids 442-860 of SEQ ID NO: 2 or at most 95% amino acid identity with amino acids 442-860 of SEQ ID NO: 2.

In other aspects of this embodiment, a BoNT/B translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 442-860 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 442-860 of SEQ ID NO: 2. In yet other aspects of this embodiment, a BoNT/B translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 442-860 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 442-860 of SEQ ID NO: 2. In still other aspects of this embodiment, a BoNT/B translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 442-860 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 442-860 of SEQ ID NO: 2.

In other aspects of this embodiment, a BoNT/B translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 442-860 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 442-860 of SEQ ID NO: 2. In yet other aspects of this embodiment, a BoNT/B translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 442-860 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 442-860 of SEQ ID NO: 2. In still other aspects of this embodiment, a BoNT/B translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 442-860 of SEQ ID NO: 2. In other aspects of this embodiment, a BoNT/B translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 442-860 of SEQ ID NO: 2.

In another embodiment, a Clostridial toxin translocation domain comprises a BoNT/C1 translocation domain. In an aspect of this embodiment, a BoNT/C1 translocation domain comprises amino acids 450-868 of SEQ ID NO: 3. In another aspect of this embodiment, a BoNT/C1 translocation domain comprises a naturally occurring BoNT/C1 translocation domain variant, such as, e.g., a translocation domain from a BoNT/C1 isoform or a translocation domain from a BoNT/C1 subtype. In another aspect of this embodiment, a BoNT/C1 translocation domain comprises amino acids 450-868 of a naturally occurring BoNT/C1 translocation domain variant of SEQ ID NO: 3, such as, e.g., amino acids 450-868 of a BoNT/C1 isoform of SEQ ID NO: 3 or amino acids 450-868 of a BoNT/C1 subtype of SEQ ID NO: 3. In still another aspect of this embodiment, a BoNT/C1 translocation domain comprises a non-naturally occurring BoNT/C1 translocation domain variant, such as, e.g., a conservative BoNT/C1 translocation domain variant, a non-conservative BoNT/C1 translocation domain variant, a BoNT/C1 chimeric translocation domain, an active BoNT/C1 translocation domain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/C1 translocation domain comprises amino acids 450-868 of a non-naturally occurring BoNT/C1 translocation domain variant of SEQ ID NO: 3, such as, e.g., amino acids 450-868 of a conservative BoNT/C1 translocation domain variant of SEQ ID NO: 3, amino acids 450-868 of a non-conservative BoNT/C1 translocation domain variant of SEQ ID NO: 3, amino acids 450-868 of an active BoNT/C1 translocation domain fragment of SEQ ID NO: 3, or any combination thereof.

In other aspects of this embodiment, a BoNT/C1 translocation domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 450-868 of SEQ ID NO: 3, at least 75% amino acid identity with amino acids 450-868 of SEQ ID NO: 3, at least 80% amino acid identity with amino acids 450-868 of SEQ ID NO: 3, at least 85% amino acid identity with amino acids 450-868 of SEQ ID NO: 3, at least 90% amino acid identity with amino acids 450-868 of SEQ ID NO: 3 or at least 95% amino acid identity with amino acids 450-868 of SEQ ID NO: 3. In yet other aspects of this embodiment, a BoNT/C1 translocation domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 450-868 of SEQ ID NO: 3, at most 75% amino acid identity with amino acids 450-868 of SEQ ID NO: 3, at most 80% amino acid identity with amino acids 450-868 of SEQ ID NO: 3, at most 85% amino acid identity with amino acids 450-868 of SEQ ID NO: 3, at most 90% amino acid identity with amino acids 450-868 of SEQ ID NO: 3 or at most 95% amino acid identity with amino acids 450-868 of SEQ ID NO: 3.

In other aspects of this embodiment, a BoNT/C1 translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 450-868 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 450-868 of SEQ ID NO: 3. In yet other aspects of this embodiment, a BoNT/C1 translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 450-868 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 450-868 of SEQ ID NO: 3. In still other aspects of this embodiment, a BoNT/C1 translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 450-868 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 450-868 of SEQ ID NO: 3.

In other aspects of this embodiment, a BoNT/C1 translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 450-868 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 450-868 of SEQ ID NO: 3. In yet other aspects of this embodiment, a BoNT/C1 translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 450-868 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 450-868 of SEQ ID NO: 3. In still other aspects of this embodiment, a BoNT/C1 translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 450-868 of SEQ ID NO: 3. In other aspects of this embodiment, a BoNT/C1 translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 450-868 of SEQ ID NO: 3.

In another embodiment, a Clostridial toxin translocation domain comprises a BoNT/D translocation domain. In an aspect of this embodiment, a BoNT/D translocation domain comprises amino acids 446-864 of SEQ ID NO: 4. In another aspect of this embodiment, a BoNT/D translocation domain comprises a naturally occurring BoNT/D translocation domain variant, such as, e.g., a translocation domain from a BoNT/D isoform or a translocation domain from a BoNT/D subtype. In another aspect of this embodiment, a BoNT/D translocation domain comprises amino acids 446-864 of a naturally occurring BoNT/D translocation domain variant of SEQ ID NO: 4, such as, e.g., amino acids 446-864 of a BoNT/D isoform of SEQ ID NO: 4 or amino acids 446-864 of a BoNT/D subtype of SEQ ID NO: 4. In still another aspect of this embodiment, a BoNT/D translocation domain comprises a non-naturally occurring BoNT/D translocation domain variant, such as, e.g., a conservative BoNT/D translocation domain variant, a non-conservative BoNT/D translocation domain variant, a BoNT/D chimeric translocation domain, an active BoNT/D translocation domain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/D translocation domain comprises amino acids 446-864 of a non-naturally occurring BoNT/D translocation domain variant of SEQ ID NO: 4, such as, e.g., amino acids 446-864 of a conservative BoNT/D translocation domain variant of SEQ ID NO: 4, amino acids 446-864 of a non-conservative BoNT/D translocation domain variant of SEQ ID NO: 4, amino acids 446-864 of an active BoNT/D translocation domain fragment of SEQ ID NO: 4, or any combination thereof.

In other aspects of this embodiment, a BoNT/D translocation domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 446-864 of SEQ ID NO: 4, at least 75% amino acid identity with amino acids 446-864 of SEQ ID NO: 4, at least 80% amino acid identity with amino acids 446-864 of SEQ ID NO: 4, at least 85% amino acid identity with amino acids 446-864 of SEQ ID NO: 4, at least 90% amino acid identity with amino acids 446-864 of SEQ ID NO: 4 or at least 95% amino acid identity with amino acids 446-864 of SEQ ID NO: 4. In yet other aspects of this embodiment, a BoNT/D translocation domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 446-864 of SEQ ID NO: 4, at most 75% amino acid identity with amino acids 446-864 of SEQ ID NO: 4, at most 80% amino acid identity with amino acids 446-864 of SEQ ID NO: 4, at most 85% amino acid identity with amino acids 446-864 of SEQ ID NO: 4, at most 90% amino acid identity with amino acids 446-864 of SEQ ID NO: 4 or at most 95% amino acid identity with amino acids 446-864 of SEQ ID NO: 4.

In other aspects of this embodiment, a BoNT/D translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 446-864 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 446-864 of SEQ ID NO: 4. In yet other aspects of this embodiment, a BoNT/D translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 446-864 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 446-864 of SEQ ID NO: 4. In still other aspects of this embodiment, a BoNT/D translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 446-864 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 446-864 of SEQ ID NO: 4.

In other aspects of this embodiment, a BoNT/D translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 446-864 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 446-864 of SEQ ID NO: 4. In yet other aspects of this embodiment, a BoNT/D translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 446-864 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 446-864 of SEQ ID NO: 4. In still other aspects of this embodiment, a BoNT/D translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 446-864 of SEQ ID NO: 4. In other aspects of this embodiment, a BoNT/D translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 446-864 of SEQ ID NO: 4.

In another embodiment, a Clostridial toxin translocation domain comprises a BoNT/E translocation domain. In an aspect of this embodiment, a BoNT/E translocation domain comprises amino acids 423-847 of SEQ ID NO: 5. In another aspect of this embodiment, a BoNT/E translocation domain comprises a naturally occurring BoNT/E translocation domain variant, such as, e.g., a translocation domain from a BoNT/E isoform or a translocation domain from a BoNT/E subtype. In another aspect of this embodiment, a BoNT/E translocation domain comprises amino acids 423-847 of a naturally occurring BoNT/E translocation domain variant of SEQ ID NO: 5, such as, e.g., amino acids 423-847 of a BoNT/E isoform of SEQ ID NO: 5 or amino acids 423-847 of a BoNT/E subtype of SEQ ID NO: 5. In still another aspect of this embodiment, a BoNT/E translocation domain comprises a non-naturally occurring BoNT/E translocation domain variant, such as, e.g., a conservative BoNT/E translocation domain variant, a non-conservative BoNT/E translocation domain variant, a BoNT/E chimeric translocation domain, an active BoNT/E translocation domain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/E translocation domain comprises amino acids 423-847 of a non-naturally occurring BoNT/E translocation domain variant of SEQ ID NO: 5, such as, e.g., amino acids 423-847 of a conservative BoNT/E translocation domain variant of SEQ ID NO: 5, amino acids 423-847 of a non-conservative BoNT/E translocation domain variant of SEQ ID NO: 5, amino acids 423-847 of an active BoNT/E translocation domain fragment of SEQ ID NO: 5, or any combination thereof.

In other aspects of this embodiment, a BoNT/E translocation domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 423-847 of SEQ ID NO: 5, at least 75% amino acid identity with amino acids 423-847 of SEQ ID NO: 5, at least 80% amino acid identity with amino acids 423-847 of SEQ ID NO: 5, at least 85% amino acid identity with amino acids 423-847 of SEQ ID NO: 5, at least 90% amino acid identity with amino acids 423-847 of SEQ ID NO: 5 or at least 95% amino acid identity with amino acids 423-847 of SEQ ID NO: 5. In yet other aspects of this embodiment, a BoNT/E translocation domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 423-847 of SEQ ID NO: 5, at most 75% amino acid identity with amino acids 423-847 of SEQ ID NO: 5, at most 80% amino acid identity with amino acids 423-847 of SEQ ID NO: 5, at most 85% amino acid identity with amino acids 423-847 of SEQ ID NO: 5, at most 90% amino acid identity with amino acids 423-847 of SEQ ID NO: 5 or at most 95% amino acid identity with amino acids 423-847 of SEQ ID NO: 5.

In other aspects of this embodiment, a BoNT/E translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 423-847 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 423-847 of SEQ ID NO: 5. In yet other aspects of this embodiment, a BoNT/E translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 423-847 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 423-847 of SEQ ID NO: 5. In still other aspects of this embodiment, a BoNT/E translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 423-847 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 423-847 of SEQ ID NO: 5.

In other aspects of this embodiment, a BoNT/E translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 423-847 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 423-847 of SEQ ID NO: 5. In yet other aspects of this embodiment, a BoNT/E translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 423-847 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 423-847 of SEQ ID NO: 5. In still other aspects of this embodiment, a BoNT/E translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 423-847 of SEQ ID NO: 5. In other aspects of this embodiment, a BoNT/E translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 423-847 of SEQ ID NO: 5.

In another embodiment, a Clostridial toxin translocation domain comprises a BoNT/F translocation domain. In an aspect of this embodiment, a BoNT/F translocation domain comprises amino acids 440-866 of SEQ ID NO: 6. In another aspect of this embodiment, a BoNT/F translocation domain comprises a naturally occurring BoNT/F translocation domain variant, such as, e.g., a translocation domain from a BoNT/F isoform or a translocation domain from a BoNT/F subtype. In another aspect of this embodiment, a BoNT/F translocation domain comprises amino acids 440-866 of a naturally occurring BoNT/F translocation domain variant of SEQ ID NO: 6, such as, e.g., amino acids 440-866 of a BoNT/F isoform of SEQ ID NO: 6 or amino acids 440-866 of a BoNT/F subtype of SEQ ID NO: 6. In still another aspect of this embodiment, a BoNT/F translocation domain comprises a non-naturally occurring BoNT/F translocation domain variant, such as, e.g., a conservative BoNT/F translocation domain variant, a non-conservative BoNT/F translocation domain variant, a BoNT/F chimeric translocation domain, an active BoNT/F translocation domain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/F translocation domain comprises amino acids 440-866 of a non-naturally occurring BoNT/F translocation domain variant of SEQ ID NO: 6, such as, e.g., amino acids 440-866 of a conservative BoNT/F translocation domain variant of SEQ ID NO: 6, amino acids 440-866 of a non-conservative BoNT/F translocation domain variant of SEQ ID NO: 6, amino acids 440-866 of an active BoNT/F translocation domain fragment of SEQ ID NO: 6, or any combination thereof.

In other aspects of this embodiment, a BoNT/F translocation domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 440-866 of SEQ ID NO: 6, at least 75% amino acid identity with amino acids 440-866 of SEQ ID NO: 6, at least 80% amino acid identity with amino acids 440-866 of SEQ ID NO: 6, at least 85% amino acid identity with amino acids 440-866 of SEQ ID NO: 6, at least 90% amino acid identity with amino acids 440-866 of SEQ ID NO: 6 or at least 95% amino acid identity with amino acids 440-866 of SEQ ID NO: 6. In yet other aspects of this embodiment, a BoNT/F translocation domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 440-866 of SEQ ID NO: 6, at most 75% amino acid identity with amino acids 440-866 of SEQ ID NO: 6, at most 80% amino acid identity with amino acids 440-866 of SEQ ID NO: 6, at most 85% amino acid identity with amino acids 440-866 of SEQ ID NO: 6, at most 90% amino acid identity with amino acids 440-866 of SEQ ID NO: 6 or at most 95% amino acid identity with amino acids 440-866 of SEQ ID NO: 6.

In other aspects of this embodiment, a BoNT/F translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 440-866 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 440-866 of SEQ ID NO: 6. In yet other aspects of this embodiment, a BoNT/F translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 440-866 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 440-866 of SEQ ID NO: 6. In still other aspects of this embodiment, a BoNT/F translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 440-866 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 440-866 of SEQ ID NO: 6.

In other aspects of this embodiment, a BoNT/F translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 440-866 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 440-866 of SEQ ID NO: 6. In yet other aspects of this embodiment, a BoNT/F translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 440-866 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 440-866 of SEQ ID NO: 6. In still other aspects of this embodiment, a BoNT/F translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 440-866 of SEQ ID NO: 6. In other aspects of this embodiment, a BoNT/F translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 440-866 of SEQ ID NO: 6.

In another embodiment, a Clostridial toxin translocation domain comprises a BoNT/G translocation domain. In an aspect of this embodiment, a BoNT/G translocation domain comprises amino acids 447-865 of SEQ ID NO: 7. In another aspect of this embodiment, a BoNT/G translocation domain comprises a naturally occurring BoNT/G translocation domain variant, such as, e.g., a translocation domain from a BoNT/G isoform or a translocation domain from a BoNT/G subtype. In another aspect of this embodiment, a BoNT/G translocation domain comprises amino acids 447-865 of a naturally occurring BoNT/G translocation domain variant of SEQ ID NO: 7, such as, e.g., amino acids 447-865 of a BoNT/G isoform of SEQ ID NO: 7 or amino acids 447-865 of a BoNT/G subtype of SEQ ID NO: 7. In still another aspect of this embodiment, a BoNT/G translocation domain comprises a non-naturally occurring BoNT/G translocation domain variant, such as, e.g., a conservative BoNT/G translocation domain variant, a non-conservative BoNT/G translocation domain variant, a BoNT/G chimeric translocation domain, an active BoNT/G translocation domain fragment, or any combination thereof. In still another aspect of this embodiment, a BoNT/G translocation domain comprises amino acids 447-865 of a non-naturally occurring BoNT/G translocation domain variant of SEQ ID NO: 7, such as, e.g., amino acids 447-865 of a conservative BoNT/G translocation domain variant of SEQ ID NO: 7, amino acids 447-865 of a non-conservative BoNT/G translocation domain variant of SEQ ID NO: 7, amino acids 447-865 of an active BoNT/G translocation domain fragment of SEQ ID NO: 7, or any combination thereof.

In other aspects of this embodiment, a BoNT/G translocation domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 447-865 of SEQ ID NO: 7, at least 75% amino acid identity with amino acids 447-865 of SEQ ID NO: 7, at least 80% amino acid identity with amino acids 447-865 of SEQ ID NO: 7, at least 85% amino acid identity with amino acids 447-865 of SEQ ID NO: 7, at least 90% amino acid identity with amino acids 447-865 of SEQ ID NO: 7 or at least 95% amino acid identity with amino acids 447-865 of SEQ ID NO: 7. In yet other aspects of this embodiment, a BoNT/G translocation domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 447-865 of SEQ ID NO: 7, at most 75% amino acid identity with amino acids 447-865 of SEQ ID NO: 7, at most 80% amino acid identity with amino acids 447-865 of SEQ ID NO: 7, at most 85% amino acid identity with amino acids 447-865 of SEQ ID NO: 7, at most 90% amino acid identity with amino acids 447-865 of SEQ ID NO: 7 or at most 95% amino acid identity with amino acids 447-865 of SEQ ID NO: 7.

In other aspects of this embodiment, a BoNT/G translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 447-865 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 447-865 of SEQ ID NO: 7. In yet other aspects of this embodiment, a BoNT/G translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 447-865 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 447-865 of SEQ ID NO: 7. In still other aspects of this embodiment, a BoNT/G translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 447-865 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 447-865 of SEQ ID NO: 7.

In other aspects of this embodiment, a BoNT/G translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 447-865 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 447-865 of SEQ ID NO: 7. In yet other aspects of this embodiment, a BoNT/G translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 447-865 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 447-865 of SEQ ID NO: 7. In still other aspects of this embodiment, a BoNT/G translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 447-865 of SEQ ID NO: 7. In other aspects of this embodiment, a BoNT/G translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 447-865 of SEQ ID NO: 7.

In another embodiment, a Clostridial toxin translocation domain comprises a TeNT translocation domain. In an aspect of this embodiment, a TeNT translocation domain comprises amino acids 458-881 of SEQ ID NO: 8. In another aspect of this embodiment, a TeNT translocation domain comprises a naturally occurring TeNT translocation domain variant, such as, e.g., a translocation domain from a TeNT isoform or a translocation domain from a TeNT subtype. In another aspect of this embodiment, a TeNT translocation domain comprises amino acids 458-881 of a naturally occurring TeNT translocation domain variant of SEQ ID NO: 8, such as, e.g., amino acids 458-881 of a TeNT isoform of SEQ ID NO: 8 or amino acids 458-881 of a TeNT subtype of SEQ ID NO: 8. In still another aspect of this embodiment, a TeNT translocation domain comprises a non-naturally occurring TeNT translocation domain variant, such as, e.g., a conservative TeNT translocation domain variant, a non-conservative TeNT translocation domain variant, a TeNT chimeric translocation domain, an active TeNT translocation domain fragment, or any combination thereof. In still another aspect of this embodiment, a TeNT translocation domain comprises amino acids 458-881 of a non-naturally occurring TeNT translocation domain variant of SEQ ID NO: 8, such as, e.g., amino acids 458-881 of a conservative TeNT translocation domain variant of SEQ ID NO: 8, amino acids 458-881 of a non-conservative TeNT translocation domain variant of SEQ ID NO: 8, amino acids 458-881 of an active TeNT translocation domain fragment of SEQ ID NO: 8, or any combination thereof.

In other aspects of this embodiment, a TeNT translocation domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 458-881 of SEQ ID NO: 8, at least 75% amino acid identity with amino acids 458-881 of SEQ ID NO: 8, at least 80% amino acid identity with amino acids 458-881 of SEQ ID NO: 8, at least 85% amino acid identity with amino acids 458-881 of SEQ ID NO: 8, at least 90% amino acid identity with amino acids 458-881 of SEQ ID NO: 8 or at least 95% amino acid identity with amino acids 458-881 of SEQ ID NO: 8. In yet other aspects of this embodiment, a TeNT translocation domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 458-881 of SEQ ID NO: 8, at most 75% amino acid identity with amino acids 458-881 of SEQ ID NO: 8, at most 80% amino acid identity with amino acids 458-881 of SEQ ID NO: 8, at most 85% amino acid identity with amino acids 458-881 of SEQ ID NO: 8, at most 90% amino acid identity with amino acids 458-881 of SEQ ID NO: 8 or at most 95% amino acid identity with amino acids 458-881 of SEQ ID NO: 8.

In other aspects of this embodiment, a TeNT translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 458-881 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 458-881 of SEQ ID NO: 8. In yet other aspects of this embodiment, a TeNT translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 458-881 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 458-881 of SEQ ID NO: 8. In still other aspects of this embodiment, a TeNT translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 458-881 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 458-881 of SEQ ID NO: 8.

In other aspects of this embodiment, a TeNT translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 458-881 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 458-881 of SEQ ID NO: 8. In yet other aspects of this embodiment, a TeNT translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 458-881 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 458-881 of SEQ ID NO: 8. In still other aspects of this embodiment, a TeNT translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 458-881 of SEQ ID NO: 8. In other aspects of this embodiment, a TeNT translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 458-881 of SEQ ID NO: 8.

In another embodiment, a Clostridial toxin translocation domain comprises a BaNT translocation domain. In an aspect of this embodiment, a BaNT translocation domain comprises amino acids 432-857 of SEQ ID NO: 9. In another aspect of this embodiment, a BaNT translocation domain comprises a naturally occurring BaNT translocation domain variant, such as, e.g., a translocation domain from a BaNT isoform or a translocation domain from a BaNT subtype. In another aspect of this embodiment, a BaNT translocation domain comprises amino acids 432-857 of a naturally occurring BaNT translocation domain variant of SEQ ID NO: 9, such as, e.g., amino acids 432-857 of a BaNT isoform of SEQ ID NO: 9 or amino acids 432-857 of a BaNT subtype of SEQ ID NO: 9. In still another aspect of this embodiment, a BaNT translocation domain comprises a non-naturally occurring BaNT translocation domain variant, such as, e.g., a conservative BaNT translocation domain variant, a non-conservative BaNT translocation domain variant, a BaNT chimeric translocation domain, an active BaNT translocation domain fragment, or any combination thereof. In still another aspect of this embodiment, a BaNT translocation domain comprises amino acids 432-857 of a non-naturally occurring BaNT translocation domain variant of SEQ ID NO: 9, such as, e.g., amino acids 432-857 of a conservative BaNT translocation domain variant of SEQ ID NO: 9, amino acids 432-857 of a non-conservative BaNT translocation domain variant of SEQ ID NO: 9, amino acids 432-857 of an active BaNT translocation domain fragment of SEQ ID NO: 9, or any combination thereof.

In other aspects of this embodiment, a BaNT translocation domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 432-857 of SEQ ID NO: 9, at least 75% amino acid identity with amino acids 432-857 of SEQ ID NO: 9, at least 80% amino acid identity with amino acids 432-857 of SEQ ID NO: 9, at least 85% amino acid identity with amino acids 432-857 of SEQ ID NO: 9, at least 90% amino acid identity with amino acids 432-857 of SEQ ID NO: 9 or at least 95% amino acid identity with amino acids 432-857 of SEQ ID NO: 9. In yet other aspects of this embodiment, a BaNT translocation domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 432-857 of SEQ ID NO: 9, at most 75% amino acid identity with amino acids 432-857 of SEQ ID NO: 9, at most 80% amino acid identity with amino acids 432-857 of SEQ ID NO: 9, at most 85% amino acid identity with amino acids 432-857 of SEQ ID NO: 9, at most 90% amino acid identity with amino acids 432-857 of SEQ ID NO: 9 or at most 95% amino acid identity with amino acids 432-857 of SEQ ID NO: 9.

In other aspects of this embodiment, a BaNT translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 432-857 of SEQ ID NO: 9. In other aspects of this embodiment, a BaNT translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 432-857 of SEQ ID NO: 9. In yet other aspects of this embodiment, a BaNT translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 432-857 of SEQ ID NO: 9. In other aspects of this embodiment, a BaNT translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 432-857 of SEQ ID NO: 9. In still other aspects of this embodiment, a BaNT translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 432-857 of SEQ ID NO: 9. In other aspects of this embodiment, a BaNT translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 432-857 of SEQ ID NO: 9.

In other aspects of this embodiment, a BaNT translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 432-857 of SEQ ID NO: 9. In other aspects of this embodiment, a BaNT translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 432-857 of SEQ ID NO: 9. In yet other aspects of this embodiment, a BaNT translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 432-857 of SEQ ID NO: 9. In other aspects of this embodiment, a BaNT translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 432-857 of SEQ ID NO: 9. In still other aspects of this embodiment, a BaNT translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 432-857 of SEQ ID NO: 9. In other aspects of this embodiment, a BaNT translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 432-857 of SEQ ID NO: 9.

In another embodiment, a Clostridial toxin translocation domain comprises a BuNT translocation domain. In an aspect of this embodiment, a BuNT translocation domain comprises amino acids 423-847 of SEQ ID NO: 10. In another aspect of this embodiment, a BuNT translocation domain comprises a naturally occurring BuNT translocation domain variant, such as, e.g., a translocation domain from a BuNT isoform or a translocation domain from a BuNT subtype. In another aspect of this embodiment, a BuNT translocation domain comprises amino acids 423-847 of a naturally occurring BuNT translocation domain variant of SEQ ID NO: 10, such as, e.g., amino acids 423-847 of a BuNT isoform of SEQ ID NO: 10 or amino acids 423-847 of a BuNT subtype of SEQ ID NO: 10. In still another aspect of this embodiment, a BuNT translocation domain comprises a non-naturally occurring BuNT translocation domain variant, such as, e.g., a conservative BuNT translocation domain variant, a non-conservative BuNT translocation domain variant, a BuNT chimeric translocation domain, an active BuNT translocation domain fragment, or any combination thereof. In still another aspect of this embodiment, a BuNT translocation domain comprises amino acids 423-847 of a non-naturally occurring BuNT translocation domain variant of SEQ ID NO: 10, such as, e.g., amino acids 423-847 of a conservative BuNT translocation domain variant of SEQ ID NO: 10, amino acids 423-847 of a non-conservative BuNT translocation domain variant of SEQ ID NO: 10, amino acids 423-847 of an active BuNT translocation domain fragment of SEQ ID NO: 10, or any combination thereof.

In other aspects of this embodiment, a BuNT translocation domain comprises a polypeptide having, e.g., at least 70% amino acid identity with amino acids 423-847 of SEQ ID NO: 10, at least 75% amino acid identity with amino acids 423-847 of SEQ ID NO: 10, at least 80% amino acid identity with amino acids 423-847 of SEQ ID NO: 10, at least 85% amino acid identity with amino acids 423-847 of SEQ ID NO: 10, at least 90% amino acid identity with amino acids 423-847 of SEQ ID NO: 10 or at least 95% amino acid identity with amino acids 423-847 of SEQ ID NO: 10. In yet other aspects of this embodiment, a BuNT translocation domain comprises a polypeptide having, e.g., at most 70% amino acid identity with amino acids 423-847 of SEQ ID NO: 10, at most 75% amino acid identity with amino acids 423-847 of SEQ ID NO: 10, at most 80% amino acid identity with amino acids 423-847 of SEQ ID NO: 10, at most 85% amino acid identity with amino acids 423-847 of SEQ ID NO: 10, at most 90% amino acid identity with amino acids 423-847 of SEQ ID NO: 10 or at most 95% amino acid identity with amino acids 423-847 of SEQ ID NO: 10.

In other aspects of this embodiment, a BuNT translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100, or 200 non-contiguous amino acid substitutions relative to amino acids 423-847 of SEQ ID NO: 10. In other aspects of this embodiment, a BuNT translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid substitutions relative to amino acids 423-847 of SEQ ID NO: 10. In yet other aspects of this embodiment, a BuNT translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 423-847 of SEQ ID NO: 10. In other aspects of this embodiment, a BuNT translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid deletions relative to amino acids 423-847 of SEQ ID NO: 10. In still other aspects of this embodiment, a BuNT translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 423-847 of SEQ ID NO: 10. In other aspects of this embodiment, a BuNT translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 non-contiguous amino acid additions relative to amino acids 423-847 of SEQ ID NO: 10.

In other aspects of this embodiment, a BuNT translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 423-847 of SEQ ID NO: 10. In other aspects of this embodiment, a BuNT translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid substitutions relative to amino acids 423-847 of SEQ ID NO: 10. In yet other aspects of this embodiment, a BuNT translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 423-847 of SEQ ID NO: 10. In other aspects of this embodiment, a BuNT translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid deletions relative to amino acids 423-847 of SEQ ID NO: 10. In still other aspects of this embodiment, a BuNT translocation domain comprises a polypeptide having, e.g., at most one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 423-847 of SEQ ID NO: 10. In other aspects of this embodiment, a BuNT translocation domain comprises a polypeptide having, e.g., at least one, two, three, four, five, six, seven, eight, nine, 10, 20, 30, 40, 50, 100 or 200 contiguous amino acid additions relative to amino acids 423-847 of SEQ ID NO: 10.

By “binding element” is meant an amino acid sequence region able to preferentially bind to a cell surface marker characteristic of the target cell under physiological conditions. The cell surface marker may comprise a polypeptide, a polysaccharide, a lipid, a glycoprotein, a lipoprotein, or may have structural characteristics of more than one of these. By “preferentially interact” is meant that the disassociation constant (K_(d)) of the binding element for the cell surface marker is at least one order of magnitude less than that of the binding element for any other cell surface marker. Preferably, the disassociation constant is at least 2 orders of magnitude less, even more preferably the disassociation constant is at least 3 orders of magnitude less than that of the binding element for any other cell surface marker to which the neurotoxin or modified neurotoxin is exposed. Examples of binding elements are described in, e.g., Steward, L. E. et al., Modified Clostridial Toxins with Enhanced Translocation Capability and Enhanced Targeting Activity, U.S. patent application Ser. No. 11/776,043 (Jul. 11, 2007); Steward, L. E. et al., Modified Clostridial Toxins with Enhanced Translocation Capabilities and Altered Targeting Activity For Clostridial Toxin Target Cells, U.S. patent application Ser. No. 11/776,052 (Jul. 11, 2007); and Steward, L. E. et al., Modified Clostridial Toxins with Enhanced Translocation Capabilities and Altered Targeting Activity For Non-Clostridial Toxin Target Cells, U.S. patent application Ser. No. 11/776,075 (Jul. 11, 2007), each of which is incorporated by reference in its entirety.

A non-limiting example of a binding element disclosed in the present specification is, e.g., a opioid peptide, such as, e.g., an enkephalin, an endomorphin, an endorphin, a dynorphin, a nociceptin or a hemorphin. Thus, in an embodiment, a binding element is derived from an opioid peptide.

In another embodiment, a binding element comprising an enkephalin peptide. In aspects of this embodiment, a binding element comprising an enkephalin peptide is derived from a Leu-enkephalin, a Met-enkephalin, a Met-enkephalin MRGL or a Met-enkephalin MRF. In other aspects of this embodiment, a binding element comprising an enkephalin peptide comprises SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55.

In other aspects of this embodiment, a binding element comprising an enkephalin peptide has, e.g., at least 70% amino acid identity with SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55, at least 75% amino acid identity with SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55, at least 80% amino acid identity with SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55, at least 85% amino acid identity with SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55, at least 90% amino acid identity with SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55 or at least 95% amino acid identity with SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55. In yet other aspects of this embodiment, a binding element comprising an enkephalin peptide has, e.g., at most 70% amino acid identity with SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55, at most 75% amino acid identity with SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55, at most 80% amino acid identity with SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55, at most 85% amino acid identity with SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55, at most 90% amino acid identity with SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55 or at most 95% amino acid identity with SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55.

In other aspects of this embodiment, a binding element comprising an enkephalin peptide has, e.g., at least one, two or three non-contiguous amino acid substitutions relative to SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55. In other aspects of this embodiment, a binding element comprising an enkephalin peptide has, e.g., at most one, two or three non-contiguous amino acid substitutions relative to SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55. In yet other aspects of this embodiment, a binding element comprising an enkephalin peptide has, e.g., at least one, two or three non-contiguous amino acid deletions relative to SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55. In yet other aspects of this embodiment, a binding element comprising an enkephalin peptide has, e.g., at most one, two or three non-contiguous amino acid deletions relative to SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55. In still other aspects of this embodiment, a binding element comprising an enkephalin peptide has, e.g., at least one, two or three non-contiguous amino acid additions relative to SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55. In yet other aspects of this embodiment, a binding element comprising an enkephalin peptide has, e.g., at most one, two or three non-contiguous amino acid additions relative to SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55.

In other aspects of this embodiment, a binding element comprising an enkephalin peptide has, e.g., at least one, two or three contiguous amino acid substitutions relative to SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55. In other aspects of this embodiment, a binding element comprising an enkephalin peptide has, e.g., at most one, two or three contiguous amino acid substitutions relative to SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55. In yet other aspects of this embodiment, a binding element comprising an enkephalin peptide has, e.g., at least one, two or three contiguous amino acid deletions relative to SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55. In yet other aspects of this embodiment, a binding element comprising an enkephalin peptide has, e.g., at most one, two or three contiguous amino acid deletions relative to SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55. In still other aspects of this embodiment, a binding element comprising an enkephalin peptide has, e.g., at least one, two or three contiguous amino acid additions relative to SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55. In yet other aspects of this embodiment, a binding element comprising an enkephalin peptide has, e.g., at most one, two or three contiguous amino acid additions relative to SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 or SEQ ID NO: 55.

In another embodiment, a binding element comprises a bovine adrenomedullary-22 (BAM22) peptide. In aspects of this embodiment, a binding element comprising a BAM22 peptide is derived from a BAM22 peptide (1-12), a BAM22 peptide (6-22), a BAM22 peptide (8-22) or a BAM22 peptide (1-22). In other aspects of this embodiment, a binding element comprising a BAM22 peptide comprises amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60 or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61.

In other aspects of this embodiment, a binding element comprising a BAM22 peptide has, e.g., at least 70% amino acid identity with amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61, at least 75% amino acid identity with amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61, at least 80% amino acid identity with amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61, at least 85% amino acid identity with amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61, at least 90% amino acid identity with amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61 or at least 95% amino acid identity with amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61.

In yet other aspects of this embodiment, a binding element comprising a BAM22 peptide has, e.g., at most 70% amino acid identity with amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61, at most 75% amino acid identity with amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61, at most 80% amino acid identity with amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61, at most 85% amino acid identity with amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61, at most 90% amino acid identity with amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61 or at most 95% amino acid identity with amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61.

In other aspects of this embodiment, a binding element comprising a BAM22 peptide has, e.g., at least one, two, three, four or five non-contiguous amino acid substitutions relative to amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61. In other aspects of this embodiment, a binding element comprising a BAM22 peptide has, e.g., at most one, two, three, four or five non-contiguous amino acid substitutions relative to amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61. In yet other aspects of this embodiment, a binding element comprising a BAM22 peptide has, e.g., at least one, two, three, four or five non-contiguous amino acid deletions relative to amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61. In yet other aspects of this embodiment, a binding element comprising a BAM22 peptide has, e.g., at most one, two, three, four or five non-contiguous amino acid deletions relative to amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61. In still other aspects of this embodiment, a binding element comprising a BAM22 peptide has, e.g., at least one, two, three, four or five non-contiguous amino acid additions relative to amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61. In yet other aspects of this embodiment, a binding element comprising a BAM22 peptide has, e.g., at most one, two, three, four or five non-contiguous amino acid additions relative to amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61.

In other aspects of this embodiment, a binding element comprising a BAM22 peptide has, e.g., at least one, two, three, four or five contiguous amino acid substitutions relative to amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61. In other aspects of this embodiment, a binding element comprising a BAM22 peptide has, e.g., at most one, two, three, four or five contiguous amino acid substitutions relative to amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61. In yet other aspects of this embodiment, a binding element comprising a BAM22 peptide has, e.g., at least one, two, three, four or five contiguous amino acid deletions relative to amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61. In yet other aspects of this embodiment, a binding element comprising a BAM22 peptide has, e.g., at most one, two, three, four or five contiguous amino acid deletions relative to amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61. In still other aspects of this embodiment, a binding element comprising a BAM22 peptide has, e.g., at least one, two, three, four or five contiguous amino acid additions relative to amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61. In yet other aspects of this embodiment, a binding element comprising a BAM22 peptide has, e.g., at most one, two, three, four or five contiguous amino acid additions relative to amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60; or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61.

In another embodiment, a binding element comprises an endomorphin peptide. In aspects of this embodiment, a binding element comprising an endomorphin peptide is derived from an endomorphin-1 or an endomorphin-2. In other aspects of this embodiment, a binding element comprising an endomorphin peptide comprises SEQ ID NO: 62 or SEQ ID NO: 63.

In other aspects of this embodiment, a binding element comprising an endomorphin peptide has, e.g., at least 70% amino acid identity with SEQ ID NO: 62 or SEQ ID NO: 63, at least 75% amino acid identity with SEQ ID NO: 62 or SEQ ID NO: 63, at least 80% amino acid identity with SEQ ID NO: 62 or SEQ ID NO: 63, at least 85% amino acid identity with SEQ ID NO: 62 or SEQ ID NO: 63, at least 90% amino acid identity with SEQ ID NO: 62 or SEQ ID NO: 63 or at least 95% amino acid identity with SEQ ID NO: 62 or SEQ ID NO: 63. In yet other aspects of this embodiment, a binding element comprising an endomorphin peptide has, e.g., at most 70% amino acid identity with SEQ ID NO: 62 or SEQ ID NO: 63, at most 75% amino acid identity with SEQ ID NO: 62 or SEQ ID NO: 63, at most 80% amino acid identity with SEQ ID NO: 62 or SEQ ID NO: 63, at most 85% amino acid identity with SEQ ID NO: 62 or SEQ ID NO: 63, at most 90% amino acid identity with SEQ ID NO: 62 or SEQ ID NO: 63 or at most 95% amino acid identity with SEQ ID NO: 62 or SEQ ID NO: 63.

In other aspects of this embodiment, a binding element comprising an endomorphin peptide has, e.g., at least one, two or three non-contiguous amino acid substitutions relative to SEQ ID NO: 62 or SEQ ID NO: 63. In other aspects of this embodiment, a binding element comprising an endomorphin peptide has, e.g., at most one, two or three non-contiguous amino acid substitutions relative to SEQ ID NO: 62 or SEQ ID NO: 63. In yet other aspects of this embodiment, a binding element comprising an endomorphin peptide has, e.g., at least one, two or three non-contiguous amino acid deletions relative to SEQ ID NO: 62 or SEQ ID NO: 63. In yet other aspects of this embodiment, a binding element comprising an endomorphin peptide has, e.g., at most one, two or three non-contiguous amino acid deletions relative to SEQ ID NO: 62 or SEQ ID NO: 63. In still other aspects of this embodiment, a binding element comprising an endomorphin peptide has, e.g., at least one, two or three non-contiguous amino acid additions relative to SEQ ID NO: 62 or SEQ ID NO: 63. In yet other aspects of this embodiment, a binding element comprising an endomorphin peptide has, e.g., at most one, two or three non-contiguous amino acid additions relative to SEQ ID NO: 62 or SEQ ID NO: 63.

In other aspects of this embodiment, a binding element comprising an endomorphin peptide has, e.g., at least one, two or three contiguous amino acid substitutions relative to SEQ ID NO: 62 or SEQ ID NO: 63. In other aspects of this embodiment, a binding element comprising an endomorphin peptide has, e.g., at most one, two or three contiguous amino acid substitutions relative to SEQ ID NO: 62 or SEQ ID NO: 63. In yet other aspects of this embodiment, a binding element comprising an endomorphin peptide has, e.g., at least one, two or three contiguous amino acid deletions relative to SEQ ID NO: 62 or SEQ ID NO: 63. In yet other aspects of this embodiment, a binding element comprising an endomorphin peptide has, e.g., at most one, two or three contiguous amino acid deletions relative to SEQ ID NO: 62 or SEQ ID NO: 63. In still other aspects of this embodiment, a binding element comprising an endomorphin peptide has, e.g., at least one, two or three contiguous amino acid additions relative to SEQ ID NO: 62 or SEQ ID NO: 63. In yet other aspects of this embodiment, a binding element comprising an endomorphin peptide has, e.g., at most one, two or three contiguous amino acid additions relative to SEQ ID NO: 62 or SEQ ID NO: 63.

In another embodiment, a binding element comprises an endorphin peptide. In aspects of this embodiment, a binding element comprising an endorphin peptide is derived from an endorphin-α, a neoendorphin-α, an endorphin-β, a neoendorphin-β or an endorphin-γ. In other aspects of this embodiment, a binding element comprising an endorphin peptide comprises SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69.

In other aspects of this embodiment, a binding element comprising an endorphin has, e.g., at least 70% amino acid identity with SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69, at least 75% amino acid identity with SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69, at least 80% amino acid identity with SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69, at least 85% amino acid identity with SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69, at least 90% amino acid identity with SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69 or at least 95% amino acid identity with SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69. In yet other aspects of this embodiment, a binding element comprising an endorphin has, e.g., at most 70% amino acid identity with SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69, at most 75% amino acid identity with SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69, at most 80% amino acid identity with SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69, at most 85% amino acid identity with SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69, at most 90% amino acid identity with SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69 or at most 95% amino acid identity with SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69.

In other aspects of this embodiment, a binding element comprising an endorphin has, e.g., at least one, two, three, four or five non-contiguous amino acid substitutions relative to SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69. In other aspects of this embodiment, a binding element comprising an endorphin has, e.g., at most one, two, three, four or five non-contiguous amino acid substitutions relative to SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69. In yet other aspects of this embodiment, a binding element comprising an endorphin has, e.g., at least one, two, three, four or five non-contiguous amino acid deletions relative to SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69. In yet other aspects of this embodiment, a binding element comprising an endorphin has, e.g., at most one, two, three, four or five non-contiguous amino acid deletions relative to SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69. In still other aspects of this embodiment, a binding element comprising an endorphin has, e.g., at least one, two, three, four or five non-contiguous amino acid additions relative to SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69. In yet other aspects of this embodiment, a binding element comprising an endorphin has, e.g., at most one, two, three, four or five non-contiguous amino acid additions relative to SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69.

In other aspects of this embodiment, a binding element comprising an endorphin has, e.g., at least one, two, three, four or five contiguous amino acid substitutions relative to SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69. In other aspects of this embodiment, a binding element comprising an endorphin has, e.g., at most one, two, three, four or five contiguous amino acid substitutions relative to SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69. In yet other aspects of this embodiment, a binding element comprising an endorphin has, e.g., at least one, two, three, four or five contiguous amino acid deletions relative to SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69. In yet other aspects of this embodiment, a binding element comprising an endorphin has, e.g., at most one, two, three, four or five contiguous amino acid deletions relative to SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69. In still other aspects of this embodiment, a binding element comprising an endorphin has, e.g., at least one, two, three, four or five contiguous amino acid additions relative to SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69. In yet other aspects of this embodiment, a binding element comprising an endorphin has, e.g., at most one, two, three, four or five contiguous amino acid additions relative to SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69.

In another embodiment, a binding element comprises a dynorphin peptide. In aspects of this embodiment, a binding element comprising a dynorphin peptide is derived from a dynorphin A, a dynorphin B (leumorphin) or a rimorphin. In other aspects of this embodiment, a binding element comprising an dynorphin peptide comprises SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 72, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80, SEQ ID NO: 81, SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 85, SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, SEQ ID NO: 90, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, SEQ ID NO: 94, SEQ ID NO: 95, SEQ ID NO: 96, SEQ ID NO: 97, SEQ ID NO: 98, SEQ ID NO: 99 or SEQ ID NO: 100.

In other aspects of this embodiment, a binding element comprising an dynorphin peptide has, e.g., at least 70% amino acid identity with SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95, at least 75% amino acid identity with SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95, at least 80% amino acid identity with SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95, at least 85% amino acid identity with SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95, at least 90% amino acid identity with SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95 or at least 95% amino acid identity with SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95. In yet other aspects of this embodiment, a binding element comprising an dynorphin peptide has, e.g., at most 70% amino acid identity with SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95, at most 75% amino acid identity with SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95, at most 80% amino acid identity with SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95, at most 85% amino acid identity with SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95, at most 90% amino acid identity with SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95 or at most 95% amino acid identity with SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95.

In other aspects of this embodiment, a binding element comprising an dynorphin peptide has, e.g., at least one, two, three, four, five, six, seven, eight, nine or ten non-contiguous amino acid substitutions relative to SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95. In other aspects of this embodiment, a binding element comprising an dynorphin peptide has, e.g., at most one, two, three, four, five, six, seven, eight, nine or ten non-contiguous amino acid substitutions relative to SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95. In yet other aspects of this embodiment, a binding element comprising an dynorphin peptide has, e.g., at least one, two, three, four, five, six, seven, eight, nine or ten non-contiguous amino acid deletions relative to SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95. In yet other aspects of this embodiment, a binding element comprising an dynorphin peptide has, e.g., at most one, two, three, four, five, six, seven, eight, nine or ten non-contiguous amino acid deletions relative to SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95. In still other aspects of this embodiment, a binding element comprising an dynorphin peptide has, e.g., at least one, two, three, four, five, six, seven, eight, nine or ten non-contiguous amino acid additions relative to SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95. In yet other aspects of this embodiment, a binding element comprising an dynorphin peptide has, e.g., at most one, two, three, four, five, six, seven, eight, nine or ten non-contiguous amino acid additions relative to SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95.

In other aspects of this embodiment, a binding element comprising an dynorphin peptide has, e.g., at least one, two, three, four, five, six, seven, eight, nine or ten contiguous amino acid substitutions relative to SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95. In other aspects of this embodiment, a binding element comprising an dynorphin peptide has, e.g., at most one, two, three, four, five, six, seven, eight, nine or ten contiguous amino acid substitutions relative to SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95. In yet other aspects of this embodiment, a binding element comprising an dynorphin peptide has, e.g., at least one, two, three, four, five, six, seven, eight, nine or ten contiguous amino acid deletions relative to SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95. In yet other aspects of this embodiment, a binding element comprising an dynorphin peptide has, e.g., at most one, two, three, four, five, six, seven, eight, nine or ten contiguous amino acid deletions relative to SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95. In still other aspects of this embodiment, a binding element comprising an dynorphin peptide has, e.g., at least one, two, three, four, five, six, seven, eight, nine or ten contiguous amino acid additions relative to SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95. In yet other aspects of this embodiment, a binding element comprising an dynorphin peptide has, e.g., at most one, two, three, four, five, six, seven, eight, nine or ten contiguous amino acid additions relative to SEQ ID NO: 70, SEQ ID NO: 79 or SEQ ID NO: 95.

In another embodiment, a binding element comprises a nociceptin peptide. In aspects of this embodiment, a binding element comprising a nociceptin peptide is derived from a nociceptin RK, a nociceptin, a neuropeptide 1, a neuropeptide 2 or a neuropeptide 3. In other aspects of this embodiment, a binding element comprising a nociceptin peptide comprises SEQ ID NO: 101, SEQ ID NO: 102, SEQ ID NO: 103, SEQ ID NO: 104, SEQ ID NO: 105, SEQ ID NO: 106, SEQ ID NO: 107, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110.

In other aspects of this embodiment, a binding element comprising a nociceptin peptide has, e.g., at least 70% amino acid identity with SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110, at least 75% amino acid identity with SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110, at least 80% amino acid identity with SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110, at least 85% amino acid identity with SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110, at least 90% amino acid identity with SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110 or at least 95% amino acid identity with SEQ ID NO:101, SEQ ID NO: 108, SEQ ID NO:109 or SEQ ID NO:110. In yet other aspects of this embodiment, a binding element comprising a nociceptin peptide has, e.g., at most 70% amino acid identity with SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110, at most 75% amino acid identity with SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110, at most 80% amino acid identity with SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110, at most 85% amino acid identity with SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110, at most 90% amino acid identity with SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110 or at most 95% amino acid identity with SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110.

In other aspects of this embodiment, a binding element comprising a nociceptin peptide has, e.g., at least one, two, three, four, five, six, seven, eight, nine or ten non-contiguous amino acid substitutions relative to SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110. In other aspects of this embodiment, a binding element comprising a nociceptin peptide has, e.g., at most one, two, three, four, five, six, seven, eight, nine or ten non-contiguous amino acid substitutions relative to SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110. In yet other aspects of this embodiment, a binding element comprising a nociceptin peptide has, e.g., at least one, two, three, four, five, six, seven, eight, nine or ten non-contiguous amino acid deletions relative to SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110. In yet other aspects of this embodiment, a binding element comprising a nociceptin peptide has, e.g., at most one, two, three, four, five, six, seven, eight, nine or ten non-contiguous amino acid deletions relative to SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110. In still other aspects of this embodiment, a binding element comprising a nociceptin peptide has, e.g., at least one, two, three, four, five, six, seven, eight, nine or ten non-contiguous amino acid additions relative to SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110. In yet other aspects of this embodiment, a binding element comprising a nociceptin peptide has, e.g., at most one, two, three, four, five, six, seven, eight, nine or ten non-contiguous amino acid additions relative to SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110.

In other aspects of this embodiment, a binding element comprising a nociceptin peptide has, e.g., at least one, two, three, four, five, six, seven, eight, nine or ten contiguous amino acid substitutions relative to SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110. In other aspects of this embodiment, a binding element comprising a nociceptin peptide has, e.g., at most one, two, three, four, five, six, seven, eight, nine or ten contiguous amino acid substitutions relative to SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110. In yet other aspects of this embodiment, a binding element comprising a nociceptin peptide has, e.g., at least one, two, three, four, five, six, seven, eight, nine or ten contiguous amino acid deletions relative to SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110. In yet other aspects of this embodiment, a binding element comprising a nociceptin peptide has, e.g., at most one, two, three, four, five, six, seven, eight, nine or ten contiguous amino acid deletions relative to SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110. In still other aspects of this embodiment, a binding element comprising a nociceptin peptide has, e.g., at least one, two, three, four, five, six, seven, eight, nine or ten contiguous amino acid additions relative to SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110. In yet other aspects of this embodiment, a binding element comprising a nociceptin peptide has, e.g., at most one, two, three, four, five, six, seven, eight, nine or ten contiguous amino acid additions relative to SEQ ID NO: 101, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110.

It is envisioned that a modified Clostridial toxin disclosed in the present specification can comprise a binding element in any and all locations with the proviso that modified Clostridial toxin is capable of performing the intoxication process. Non-limiting examples include, locating a binding element at the amino terminus of a modified Clostridial toxin; locating a binding element between a Clostridial toxin therapeutic element and a translocation element of a modified Clostridial toxin; and locating a binding element at the carboxyl terminus of a modified Clostridial toxin. Other non-limiting examples include, locating a binding element between a Clostridial toxin enzymatic domain and a Clostridial toxin translocation domain of a modified Clostridial toxin. The enzymatic domain of naturally-occurring Clostridial toxins contains the native start methionine. Thus, in domain organizations where the enzymatic domain is not in the amino-terminal location an amino acid sequence comprising the start methionine should be placed in front of the amino-terminal domain. Likewise, where a binding element is in the amino-terminal position, an amino acid sequence comprising a start methionine and a protease cleavage site may be operably-linked in situations in which a binding element requires a free amino terminus, see, e.g., Shengwen Li et al., Degradable Clostridial Toxins, U.S. patent application Ser. No. 11/572,512 (Jan. 23, 2007), which is hereby incorporated by reference in its entirety. In addition, it is known in the art that when adding a polypeptide that is operably-linked to the amino terminus of another polypeptide comprising the start methionine that the original methionine residue can be deleted.

Thus, in an embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a binding element, a translocation element, an exogenous protease cleavage site and a therapeutic element (FIG. 20A). In an aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a binding element, a Clostridial toxin translocation domain, an exogenous protease cleavage site and a Clostridial toxin enzymatic domain.

In another embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a binding element, a therapeutic element, an exogenous protease cleavage site, and a translocation element (FIG. 20B). In an aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a binding element, a Clostridial toxin enzymatic domain, an exogenous protease cleavage site, a Clostridial toxin translocation domain.

In yet another embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a therapeutic element, an exogenous protease cleavage site, a binding element, and a translocation element (FIG. 21A). In an aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin enzymatic domain, an exogenous protease cleavage site, a binding element, and a Clostridial toxin translocation domain.

In yet another embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a translocation element, an exogenous protease cleavage site, a binding element, and a therapeutic element (FIG. 21B). In an aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin translocation domain, a binding element, an exogenous protease cleavage site and a Clostridial toxin enzymatic domain.

In another embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a therapeutic element, a binding element, an exogenous protease cleavage site, and a translocation element (FIG. 21C). In an aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin enzymatic domain, a binding element, an exogenous protease cleavage site, a Clostridial toxin translocation domain.

In yet another embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a translocation element, a binding element, an exogenous protease cleavage site and a therapeutic element (FIG. 21D). In an aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin translocation domain, a binding element, an exogenous protease cleavage site and a Clostridial toxin enzymatic domain.

In still another embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a therapeutic element, an exogenous protease cleavage site, a translocation element, and a binding element (FIG. 22A). In an aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin enzymatic domain, an exogenous protease cleavage site, a Clostridial toxin translocation domain, and a binding element.

In still another embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a translocation element, an exogenous protease cleavage site, a therapeutic element and a binding element, (FIG. 22B). In an aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin translocation domain, a binding element, an exogenous protease cleavage site and a Clostridial toxin enzymatic domain.

In a particularly preferred embodiment, the single-chain neurotoxin or neurotoxin derivative of the invention, altered as indicated above, is further modified to remove other incidental endogenous proteolytic sites such as those cleaved by trypsin, Arg C protease, chymotrypsin, or host cell proteases. As indicated below, modification of the primary amino acid sequences in these regions to confer protease resistance can increase the yield of the neurotoxin and reduce the toxicity of the single-chain neurotoxin prior to cleavage and activation.

In another preferred embodiment, the recombinant modified single-chain neurotoxin is further modified by joining the chain to a binding tag comprising one member of a specific binding complex. By “specific binding complex” is meant two or more chemical or biochemical entities that will bind each other under defined environmental conditions and which will not significantly bind other chemical or biochemical entities present in the environment under the same conditions. Examples of members of a specific binding complex include, without limitation, an antibody and its antigen, a lectin and its target carbohydrate, a nucleic acid strand and its complementary nucleic acid strand, a cell surface receptor and its ligand, a metal and a compound able to form a coordination or chelation complex with that metal, and the like.

In this embodiment, the binding tag may be joined to the single-chain toxin through a linker, preferably a cleavable linker. Examples of possible linkers, while not an exhaustive list, include 1) aliphatic dicarboxylic acids of the formula HOOC—(CH₂)_(n)—COOH, where n=1-12 (may be linked at a free amino group); 2) HO—(CH₂)_(n)—COOH, where n>10 (suitable for attachment at the amino terminus of the polypeptide), 3) substituted polybenzene structures, and 4) a N-hydroxysuccinimide (NHS) ester linker. The use of an linker containing an ester permits cleavage of the ester linker following use in the purification of the single-chain neurotoxin under relatively mild acidic conditions.

Alternatively, and most preferably, the binding tag may comprise some or all of the amino acid sequence of an appropriately chosen polypeptide coexpressed with the single-chain toxin as a fusion protein; such polypeptides may comprise, without limitation, the maltose binding domain of maltose binding protein (MBP), a polyhistidine peptide like HIS₆, the calmodilin binding domain of calmodulin binding protein, the glutathione binding domain of glutathione-S-transferase, FLAG, human Influenza virus hemaglutinin (HA), human p62c-Myc protein (c MYC), Vesicular Stomatitis Virus Glycoprotein (VSV-G), Substance P, glycoprotein-D precursor of Herpes simplex virus (HSV), V5, AU1 and AU5, streptavidin binding peptide (strep), and biotin or a biotinylation sequence. Non-limiting examples of specific protocols for selecting, making and using an appropriate binding peptide are described in, e.g., Epitope Tagging, pp. 17.90-17.93 (Sambrook and Russell, eds., Molecular Cloning A Laboratory Manual, Vol. 3, 3rd ed. 2001); Antibodies: A Laboratory Manual (Edward Harlow & David Lane, eds., Cold Spring Harbor Laboratory Press, 2nd ed. 1998); and Using Antibodies: A Laboratory Manual Portable Protocol No. I (Edward Harlow & David Lane, Cold Spring Harbor Laboratory Press, 1998). In addition, non-limiting examples of binding tags as well as well-characterized reagents, conditions and protocols are readily available from commercial vendors that include, without limitation, BD Biosciences-Clontech, Palo Alto, Calif.; BD Biosciences Pharmingen, San Diego, Calif.; Invitrogen, Inc, Carlsbad, Calif.; QIAGEN, Inc., Valencia, Calif.; and Stratagene, La Jolla, Calif. These protocols are routine procedures well within the scope of one skilled in the art and from the teaching herein.

Thus, in an embodiment, a modified Clostridial toxin disclosed in the present specification can further comprise a binding tag. In another embodiment, a modified Clostridial toxin disclosed in the present specification can further comprises a plurality of binding tags. In aspects of this embodiment, a modified Clostridial toxin can comprise, e.g., at least 1 binding tag, at least 2 binding tags, at least 3 binding tags, at least 4 binding tags or at least 5 binding tags. In other aspects of this embodiment, a modified Clostridial toxin can comprise, e.g., at most 1 binding tag, at most 2 binding tags, at most 3 binding tags, at most 4 binding tags or at most 5 binding tags. In another aspect of this embodiment, a modified Clostridial toxin can comprise one or more copies of the same binding tag, one or more copies of different binding tag, or any combination thereof.

The location of a binding tag can be in various positions, including, without limitation, at the amino terminus of a modified Clostridial toxin, within a modified Clostridial toxin, or at the carboxyl terminus of a modified Clostridial toxin. Thus, in an embodiment, a binding tag is located at the amino-terminus of a modified Clostridial toxin. In such a location, a start methionine should be placed in front of the binding tag. In addition, it is known in the art that when adding a polypeptide that is operably-linked to the amino terminus of another polypeptide comprising the start methionine that the original methionine residue can be deleted. This is due to the fact that the added polypeptide will contain a new start methionine and that the original start methionine may reduce optimal expression of the fusion protein. In aspects of this embodiment, a binding tag located at the amino-terminus of a modified Clostridial toxin disclosed in the present specification can be, e.g., a FLAG Express™ binding tag, a human Influenza virus hemaglutinin (HA) binding tag, a human p62c-Myc protein (c MYC) binding tag, a Vesicular Stomatitis Virus Glycoprotein (VSV-G) binding tag, a Substance P binding tag, a glycoprotein-D precursor of Herpes simplex virus (HSV) binding tag, a V5 binding tag, a AU1 binding tag, a AU5 binding tag, a polyhistidine binding tag, a streptavidin binding peptide binding tag, a biotin binding tag, a biotinylation binding tag, a glutathione binding domain of glutathione-S-transferase, a calmodulin binding domain of the calmodulin binding protein or a maltose binding domain of the maltose binding protein.

In another embodiment, an epitope-binding region is located at the carboxyl-terminus of a modified Clostridial toxin. In aspects of this embodiment, an epitope-binding region located at the carboxyl-terminus of a modified Clostridial toxin disclosed in the present specification can be, e.g., a FLAG Express™ binding tag, a human Influenza virus hemaglutinin (HA) binding tag, a human p62c-Myc protein (c MYC) binding tag, a Vesicular Stomatitis Virus Glycoprotein (VSV-G) binding tag, a Substance P binding tag, a glycoprotein-D precursor of Herpes simplex virus (HSV) binding tag, a V5 binding tag, a AU1 binding tag, a AU5 binding tag, a polyhistidine binding tag, a streptavidin binding peptide binding tag, a biotin binding tag, a biotinylation binding tag, a glutathione binding domain of glutathione-S-transferase, a calmodulin binding domain of the calmodulin binding protein or a maltose binding domain of the maltose binding protein.

Additionally, the binding tag may be constructed to have a protease cleavage site between itself and either the amino terminus or the carboxyl terminus of the single-chain toxin so as be removable following purification of the peptide. The proteolytic cleavage site may be designed to be cleaved by the same activator protease chosen to nick the single-chain toxin between the H and L chains.

It is therefore an object of the invention to provide a recombinant activatable single-chain neurotoxin molecule that has reduced toxicity compared to the native neurotoxin until activated by reaction with a non-clostridial protease. The single-chain neurotoxin is more easily purified, is less dangerous to handle in the purification process, and can be optionally modified to give the toxin more desirable properties.

It is also an object of the invention to provide an method of making a recombinant activatable single-chain neurotoxin by modifying the nucleotide sequence encoding the neurotoxin to replace the native amino acid proteolytic cleavage sequence separating the H and L chain with an amino acid sequence stable to indigenous clostridial or host cell proteases but susceptible to cleavage by chosen protease in vitro.

It is further an object of the present invention to provide more stable neurotoxin polypeptides through modification of the nucleotide sequence of the coding region of the H and L chains thereof, removing incidental proteolytic cleavage sites by causing the replacement of labile amino acids with other amino acid residues which confer upon the toxin resistance to undesired proteolytic degradation.

Additionally, it is an object of the invention to provide methods of purifying recombinant neurotoxins as a single-chain by joining the expressed single-chain neurotoxin to a binding moiety comprising partner of a specific binding complex which can be used in the affinity purification with the binding partner comprising the other half of the binding complex. Purification can be performed batch-wise or in a chromatography column. The binding moiety may then be removed following the affinity step, and separated from the neurotoxin.

It is also an object of the invention to provide single-chain recombinant modified neurotoxin molecules for use as therapeutic agents. The modified neurotoxin molecules may have an altered target specificity or an altered activity compared to the native neurotoxin from which it is derived, or both.

Another aspect of the present invention provides a method of activating an activatable polypeptide disclosed in the present specification, such method comprising the step of incubating the activatable polypeptide with an exogenous protease, wherein the exogenous protease can cleave the exogenous protease cleavage site present in the polypeptide and wherein cleavage of the activatable polypeptide by the exogenous protease converts the activatable polypeptide from its single-chain polypeptide form into its di-chain form, thereby activating the polypeptide.

Aspects of the present invention provide, in part, an exogenous protease. As used herein, the term “exogenous protease” means any protease capable of selectively cleaving the P1-P1′ scissile bond comprising the exogenous protease cleavage site, with the proviso that the exogenous protease is not a human protease or a protease being expressed by the host cell expressing a construct encoding an activatable polypeptide disclosed in the present specification. As used herein, the term “selectively” means having a highly preferred activity or effect. Thus, with reference to an exogenous protease, there is a discriminatory proteolytic cleavage of the P1-P1′ scissile bond comprising the exogenous protease cleavage site. It is envisioned that any and all proteases capable of selectively cleaving the P1-P1′ scissile bond comprising the exogenous protease cleavage site can be useful in the disclosed methods. As a non-limiting example, a bovine enterokinse can selectively cleave a bovine enterokinse cleavage site, a tobacco etch virus protease can selectively cleave a tobacco etch virus protease cleavage site, a human rhinovirus 3C protease can selectively cleave a human rhinovirus 3C protease cleavage site, a subtilisin can selectively cleave a subtilisin cleavage site, a hydroxylamine can selectively cleave a hydroxylamine cleavage site, and a SUMO/ULP-1 protease can selectively cleave a SUMO/ULP-1 protease cleavage site.

A therapeutic agent useful in the invention generally is administered as a pharmaceutical acceptable composition comprising a modified neurotoxin as disclosed in the present specification. As used herein, the term “pharmaceutically acceptable” means any molecular entity or composition that does not produce an adverse, allergic or other untoward or unwanted reaction when administered to an individual. As used herein, the term “pharmaceutically acceptable composition” is synonymous with “pharmaceutical composition” and means a therapeutically effective concentration of an active ingredient, such as, e.g., any of the modified neurotoxins disclosed in the present specification. A pharmaceutical composition comprising a modified neurotoxin is useful for medical and veterinary applications. A pharmaceutical composition may be administered to a patient alone, or in combination with other supplementary active ingredients, agents, drugs or hormones. The pharmaceutical compositions may be manufactured using any of a variety of processes, including, without limitation, conventional mixing, dissolving, granulating, dragee-making, levigating, emulsifying, encapsulating, entrapping, and lyophilizing. The pharmaceutical composition can take any of a variety of forms including, without limitation, a sterile solution, suspension, emulsion, lyophilizate, tablet, pill, pellet, capsule, powder, syrup, elixir or any other dosage form suitable for administration.

It is also envisioned that a pharmaceutical composition comprising a modified neurotoxin can optionally include a pharmaceutically acceptable carriers that facilitate processing of an active ingredient into pharmaceutically acceptable compositions. As used herein, the term “pharmacologically acceptable carrier” is synonymous with “pharmacological carrier” and means any carrier that has substantially no long term or permanent detrimental effect when administered and encompasses terms such as “pharmacologically acceptable vehicle, stabilizer, diluent, additive, auxiliary or excipient.” Such a carrier generally is mixed with an active compound, or permitted to dilute or enclose the active compound and can be a solid, semi-solid, or liquid agent. It is understood that the active ingredients can be soluble or can be delivered as a suspension in the desired carrier or diluent. Any of a variety of pharmaceutically acceptable carriers can be used including, without limitation, aqueous media such as, e.g., water, saline, glycine, hyaluronic acid and the like; solid carriers such as, e.g., mannitol, lactose, starch, magnesium stearate, sodium saccharin, talcum, cellulose, glucose, sucrose, magnesium carbonate, and the like; solvents; dispersion media; coatings; antibacterial and antifungal agents; isotonic and absorption delaying agents; or any other inactive ingredient. Selection of a pharmacologically acceptable carrier can depend on the mode of administration. Except insofar as any pharmacologically acceptable carrier is incompatible with the active ingredient, its use in pharmaceutically acceptable compositions is contemplated. Non-limiting examples of specific uses of such pharmaceutical carriers can be found in PHARMACEUTICAL DOSAGE FORMS AND DRUG DELIVERY SYSTEMS (Howard C. Ansel et al., eds., Lippincott Williams & Wilkins Publishers, 7^(th) ed. 1999); REMINGTON: THE SCIENCE AND PRACTICE OF PHARMACY (Alfonso R. Gennaro ed., Lippincott, Williams & Wilkins, 20 ed. 2000); GOODMAN & GILMAN'S THE PHARMACOLOGICAL BASIS OF THERAPEUTICS (Joel G. Hardman et al., eds., McGraw-Hill Professional, 10^(th) ed. 2001); and HANDBOOK OF PHARMACEUTICAL EXCIPIENTS (Raymond C. Rowe et al., APhA Publications, 4^(th) edition 2003). These protocols are routine procedures and any modifications are well within the scope of one skilled in the art and from the teaching herein.

It is further envisioned that a pharmaceutical composition disclosed in the present specification can optionally include, without limitation, other pharmaceutically acceptable components (or pharmaceutical components), including, without limitation, buffers, preservatives, tonicity adjusters, salts, antioxidants, osmolality adjusting agents, physiological substances, pharmacological substances, bulking agents, emulsifying agents, wetting agents, sweetening or flavoring agents, and the like. Various buffers and means for adjusting pH can be used to prepare a pharmaceutical composition disclosed in the present specification, provided that the resulting preparation is pharmaceutically acceptable. Such buffers include, without limitation, acetate buffers, citrate buffers, phosphate buffers, neutral buffered saline, phosphate buffered saline and borate buffers. It is understood that acids or bases can be used to adjust the pH of a composition as needed. Pharmaceutically acceptable antioxidants include, without limitation, sodium metabisulfite, sodium thiosulfate, acetylcysteine, butylated hydroxyanisole and butylated hydroxytoluene. Useful preservatives include, without limitation, benzalkonium chloride, chlorobutanol, thimerosal, phenylmercuric acetate, phenylmercuric nitrate, a stabilized oxy chloro composition, such as, e.g., PURITE® and chelants, such as, e.g., DTPA or DTPA-bisamide, calcium DTPA, and CaNaDTPA-bisamide. Tonicity adjustors useful in a pharmaceutical composition include, without limitation, salts such as, e.g., sodium chloride, potassium chloride, mannitol or glycerin and other pharmaceutically acceptable tonicity adjustor. The pharmaceutical composition may be provided as a salt and can be formed with many acids, including but not limited to, hydrochloric, sulfuric, acetic, lactic, tartaric, malic, succinic, etc. Salts tend to be more soluble in aqueous or other protonic solvents than are the corresponding free base forms. It is understood that these and other substances known in the art of pharmacology can be included in a pharmaceutical composition useful in the invention.

In an embodiment, a therapeutic agent is a pharmaceutical composition comprising a modified neurotoxin. In an aspect of this embodiment, a pharmaceutical composition comprises an unactivated, single-chain for of the modified toxin. In another aspect of this embodiment, a pharmaceutical composition comprises an activated di-chain form of the modified toxin. In other aspects of this embodiment, a pharmaceutical composition comprising a modified neurotoxin further comprises a pharmacological carrier, a pharmaceutical component, or both a pharmacological carrier and a pharmaceutical component. In other aspects of this embodiment, a pharmaceutical composition comprising a modified neurotoxin further comprises at least one pharmacological carrier, at least one pharmaceutical component, or at least one pharmacological carrier and at least one pharmaceutical component.

It is also an object of the invention to provide a single-chain activatable recombinant neurotoxin that may be more easily purified than the wild type neurotoxin. Such a neurotoxin permits the large scale preparation of properly folded highly pure toxin for clinical use.

EXAMPLES

The following Examples serve to illustrate particular embodiments of the invention, and do not limit the scope of the invention defined in the claims in any way.

Example 1 Construction of an Expression Vector Containing a Single-Chain TeNT Coding Region

The present invention can be exemplified describing the construction of a plasmid that will express TeNT in E. coli as a single protein that is readily purified, i.e., by affinity chromatography. TeNT can be chosen as a pilot system because (i) the availability of an excellent vaccine greatly reduces the risk of its handling and (ii) it is the most comprehensively studied of the toxins in terms of expressing HC and LC domains. However, those of skill in the art will understand that the same or similar strategies may be employed using any di-chain or binary toxin or other bioactive molecule expressed as a single polypeptide and activated by proteolytic cleavage. Single chain molecules were constructed containing the wild type TeNT L chain and a mutated version of the TeNT light chain wherein a glutamic acid residue at position 234 is changed to an alanine (termed “E234A”, Ala²³⁴, or “the E234A mutant light chain”), respectively. This latter mutation results in an inactive TeNT light chain, and a plasmid encoding the E234A mutant light chain (pMAL-E234A) was constructed as described in Li et al., Biochemistry 33:7014-7020 (1994) (hereby incorporated by reference herein). The following protocol is used for the construction of each single-chain toxin.

The vector pTrcHisA, purchased from Invitrogen, is modified using a Stratagene QuickChange® site-directed mutagenesis kit (for site-directed mutagenesis techniques, see e.g., Smith et al., J. Biol. Chem. 253:6651-6560 (1979); incorporated by reference herein in its entirety) to create two extra restriction sites (SalI and HindIII) upstream of the nucleotides encoding a pre-existing enterokinase (EK) cleavage site. The plasmid also contains a translational start codon (ATG) followed by a run of codons encoding 6 histidine residues immediately upstream of the enterokinase cleavage site. A multiple cloning site containing Bam HI, XhoI, Bgl II, Pst I, Kpn I, Eco RI BstB I and Hind III cleavage sites is located immediately downstream of the EK site; the Hind III site is removed by site-directed mutagenesis. The following primers are employed to insert the restriction sites (underlined) upstream of the EK cleavage site:

(SEQ ID NO: 111) GACTGGTGGACAGCAAGTCGACCGGAAGCTTTACGACGATGACG,                Sal I    Hind III and (SEQ ID NO: 112) CGTCATCGTCGTAAAGCTTCCGGTCGACTTGCTGTCCACCAGTC             Hind III  Sal I

The resulting plasmid contains both Sal I and Hind III sites located at the 5′ side of the nucleotide sequence encoding the bovine enterokinase (EK) cleavage site.

The nucleotide sequence encoding the wild-type TeNT L chain is obtained from plasmid pMAL-LC, described in Li et al., Biochemistry 33, 7014-7020 (1994), incorporated by reference herein. The plasmid encodes the TeNT light chain as a fusion protein with maltose binding protein (MBP) located immediately upstream of the coding sequence for the L chain. The MBP and L chain portions of the fusion protein are designed to contain the cleavage site for human blood coagulation factor Xa (Ile-Glu-Gly-Arg) to facilitate removal of the MBP once affinity purification has been performed.

The DNA fragment containing the coding sequence of the L chain is excised from plasmid pMAL-LC by digesting the plasmid with Sal I and Hind III, gel purifying the resulting DNA fragment containing the L chain, and ligating this fragment into plasmid pTrcHisA at the newly created Sal I and Hind III sites upstream of the EK site. This fragment results in the excision of the maltose binding protein sequences from the N terminus of the L chain.

An identical procedure is used to subclone the DNA fragment containing a mutant L chain from plasmid pMAL-LC-Ala²³⁴, in which a single amino acid change is made at amino acid 234 of the L chain, substituting the native glutamic acid with alanine. This change is sufficient to abrogate the zinc endopeptidase activity of the L chain, and to render non-toxic a reconstituted tetanus toxin containing native H chain and the Ala²³⁴ L chain.

The DNA fragment containing the H chain is obtained from plasmid pMAL-HC; construction of this vector is described in Li et al., J. Biochem. 125:1200-1208 (1999), hereby incorporated by reference herein. Briefly, the gene encoding the H chain is constructed by assembling three DNA fragments containing different portions of the H chain coding sequence which had been cloned into separate plasmids. The fragments comprising the amino terminal half of the H are first amplified using standard polymerase chain reaction methods (see, e.g., Mullis, U.S. Pat. No. 4,683,202 and Mullis et al., U.S. Pat. No. 4,800,159, both incorporated by reference herein in their entirety) and the following primers: PCR primers a (containing a Xba I cleavage site) and b (containing a Bgl II cleavage site) (SEQ ID NO: 113 and 114, respectively) are used to amplify the H chain fragment contained in a plasmid termed pTet8; PCR primers c (containing a Bgl II cleavage site) and d (containing both a Hind III and a Sal I cleavage site) (SEQ ID NO: 115 and 116, respectively) are used to amplify the H chain fragment contained in a plasmid termed pTet14. The nucleotide sequences of these primer are provided below, with restriction sites underlined.

(SEQ ID NO: 113) AATAGATCTAGATCATTAACAGATTTAGGA (a) (SEQ ID NO: 114) TTCTAAAGATCTATACATTTGATAACT (b) (SEQ ID NO: 115) ATGTATAGATCTTTAGAATATCAAGTA (c) (SEQ ID NO: 116) ATCGATAAGCTTTTATCAGTCGACCCAACAATCCAGATTTTTAGA (d)

Following PCR amplification and gel purification of the amplified H chain fragments, each fragment is digested with Bgl II and ligated to yield the complete N terminal half of the H chain coding region. This ligation product is then digested with Xba I and Hind III and subcloned into the multiple cloning site of pMAL-c2-T (the plasmid being also cut with Xba I and Hind III), which is located downstream of the coding region for MBP and the factor Xa site. pMAL-c2 is a commercially available vector well known to those of skill in the art. The resulting plasmid is pMAL-H_(N).

The entire H chain coding region is assembled as follows. The pMAL-H_(N) plasmid is digested with Sac I and Sal I to yield the DNA fragment encoding the N-terminus of the H chain. Plasmid pTet215 is digested with Sal I and Bam HI to yield the DNA fragment encoding the H chain carboxyl terminus. The vector pMAL-c2-T is digested with Sac I and Bam HI, and ligated to the digested H chain fragments, which will assemble in the proper orientation due to the use of distinct endonucleases. The resulting plasmid is pMAL-HC.

The DNA fragments encoding the H and L chains (including Ala²³⁴ L chain) are cut and purified directly from pMAL-LC or pMALE234A and pMAL-HC constructs and subcloned into the modified pTrcHisA vector described above. The H chain was first ligated into the modified vector at the Bam HI site immediately downstream of the EK site, and the resulting plasmid was gel purified. Following digestion of this plasmid with Hind III and Sal I, the L chain was ligated at a position just upstream of the EK cleavage site.

The resulting plasmid construct contains the nucleotide sequence encoding the single-chain toxin protein, comprising (from amino to carboxyl terminus): six histidine residues (the His tag), followed by the L chain, an enterokinase cleavage site, and the H chain. The translated junction between the L and H chains containing the EK cleavage site (SEQ ID NO: 21) is shown below (in the direction from N-terminus to C-terminus) and in FIG. 1.

SEQ ID NO: 117                               EK site SKLIGLCKKIIPPTNIRENLYNRTA-GEKLYDDDDKDRWGSSR-SLTDLGGELCIKNEDLTFIAEKN         L chain            interchain loop         H chain

To allow expression of the two chains as a single unit, a nucleotide sequence comprising a stop codon present at the 3′ end of the L chain coding sequence in the pMAL-LC is removed by site-directed mutagenesis using two primers (SEQ ID NO: 118 and 119), resulting in a single reading frame containing both H and L chains.

AATAGAACTGCAGGAGAAAAGCTTTACGACGATGAC, (SEQ ID NO: 118) TGATAA (deleted stop codon; coding strand) and GTCATCGTCGTAAAGCTTTTCTCCTGCAGTTCTATT (SEQ ID NO: 119) TTATCA (deleted stop codon; non-coding strand)

The resulting pTrcHisA-based construct is transformed into E. coli strain JM109 by heat shock using the method of Hanahan, and transformant colonies are isolated on Luria agar plates containing 100 μg/ml ampicillin. Plasmids are purified from these transformants and the insertions are confirmed by analytical restriction endonuclease digestion and agarose gel electrophoresis.

Example 2 Expression and Physical Characterization of Single-Chain TeNT

Expression of the pTrcHisA-based single-chain TeNT construct (under control of a hybrid trp/lac promoter) is induced by addition of 1 mM IPTG (isopropyl thio-galactopyranoside) to a confluent culture of a representative transformant clone in 200 ml Luria broth containing 100 μg/ml ampicillin and incubating further at 37° C. for 16 hours before cell harvest by centrifugation.

The cell pellets are resuspended in 30 ml Buffer A (20 mM Na₂PO₄, 500 mM NaCl (pH 7.8)), then lysed by ultrasonication at 4° C., using 10-second bursts at a medium setting. Insoluble debris is removed by centrifugation at 9,000×g for 30 min at 4° C., and the supernatant recovered by centrifugation.

The supernatant containing each single-chain construct is incubated for 20 minutes at 22° C. with 2 ml of nickel-ion resin (Invitrogen Corp.) for affinity purification by means of chelation between the histidine residues at the amino terminus of the single-chain toxin molecule and the nickel. The resins were then load onto mini columns and washed with 200 ml of washing buffer (20 mM Na₂PO₄, 500 mM NaCl (pH 6.0)) to remove any non-specifically bound material, the recombinant single-chain proteins are eluted on 0.5 ml fractions with 8-15 ml of 100 mM imidazole in Buffer A. The concentration of the eluted single-chains was measured by Bradford's protein assay (Bio-Rad Laboratories); approximately 1 milligram of the fusion protein was recovered.

Example 3 SDS-PAGE and Western Blot Analysis of Recombinant Single-Chain TeNT

The single-chain TeNT constructs are grown in Luria broth containing ampicillin at 37° C., and aliquots taken both before and after induction of protein expression with IPTG. Crude cell extracts are prepared for SDS-PAGE by dilution in sample buffer under reducing conditions in the presence of β-mercaptoethanol (BME). Following SDS-PAGE electrophoresis, the separated proteins are Western-blotted as follows: the proteins are electrophoretically transferred to a polyvinylidenedifluoride (PVDF) membrane using standard methods (see, e.g., Sambrook et al., Molecular Cloning, A Laboratory Manual (2d ed. Cold Spring Harbor Laboratory Press 1989), hereby incorporated by reference in its entirety), the membrane treated to reduce background Ig binding, and then probed using an anti-His₆ antibody, followed by detection using an alkaline phosphatase-conjugated secondary antibody and development with a 5-bromo-4-chloro-3-indolyl-phosphate/nitro blue tetrazolium substrate.

As shown in lanes 1 and 2 of FIG. 2A, the Western blot revealed no detectable TeNT expression before induction of protein synthesis; by contrast, a single band of approximate molecular weight 150 kDa was revealed in the aliquots taken following protein induction (See lanes 3 and 4.) In FIG. 2A, lanes 1 and 3 are the WT light chain construct and lanes 2 and 4 contain the E234A mutant construct.

FIG. 2B is a Western blot of IPTG-induced cell extracts from cells transformed with the E234A construct. Significantly, no discernable lower molecular weight proteolytic cleavage products of the light chain were observed, providing evidence for the relative stability of the single-chain toxin following expression and purification.

FIG. 3 shows the results of a second experiment, in which affinity purified recombinant single-chain (SC) TeNT is nicked with enterokinase as follows. Thirty micrograms of purified single-chain toxin are incubated with 1 unit of enterokinase in a solution containing 50 mM Tris-HCl (pH 8.0), 1 mM CaCl₂ and 0.1% Tween-20(v/v). As a control, the recombinant protein is incubated in the same reaction mixture containing no EK. These samples, plus an aliquot of native (non-recombinant) TeNT are subjected to SDS-PAGE in an 8% polyacrylamide gel under either reducing (+BME) or non-reducing (−BME) conditions. The resulting gel is used both for a Western blot and subsequent detection using anti-H claim antibodies (FIG. 3B), and direct staining with Coomassie Blue (FIG. 3A).

As indicated by FIG. 3, under non-reducing conditions all three samples (Native TeNT (Lane 1), unnicked recombinant toxin (Lane 2), and enterokinase nicked recombinant toxin (Lane 3)) will migrate as doublets (apparently different conformers that resolve into a single band upon reduction) with essentially indistinguishable apparent molecular weights of about 150 kDa. The non-reducing gel confirms that 1) high levels of expression are obtained, 2) the disulfide bonds linking the light and heavy chains are fully formed, and 3) the recombinant single-chain toxin is not subject to observable proteolytic degradation.

By contrast, under reducing conditions wild-type and nicked recombinant toxin yield an H chain having a molecular weight of about 100 kDa by both Western blot and Coomassie staining. Additionally, in the Coomassie stained gel, both of these samples also show a lower molecular weight species of about 50 kDa, corresponding to the L chain. The wild-type L chain will migrate with a lower apparent molecular weight than that of the recombinant L chain, which has 22 additional amino acid residues due to the presence of the His₆ moiety and a modified EK cleavage site-containing interchain junction region. The unnicked recombinant toxin (Lane 2) migrates as a single band with an apparent molecular weight of about 150 kDa. Notably, no trace of the unnicked toxin is seen in lane 3, indicating the effectiveness of enterokinase treatment.

Example 4 In Vitro Toxin-Induced Paralysis by Recombinant Single-Chain TeNT

The biological activity of the recombinant TeNT is also examined and compared to wild-type toxin using mouse phrenic nerve hemi-diaphragm, since the native toxin is known to cause neuromuscular paralysis, albeit at higher concentrations than act in the CNS. For this experiment, mouse left phrenic nerve-hemidiaphragm is dissected from mice (T/O strain, 4-week old and ˜20 g in weight) and immediately transferred into a closed circulatory superfusion system containing 10 ml of Krebs-Ringer solution (118 mM NaCl, 4.7 mM KCl, 1.2 mM MgSO₄, 2.5 mM CaCl₂, 23.8 mM NaHCO₄, 1.2 mM KH₂PO₄, 11.7 mM glucose (pH 7.4)), bubbled with 95% O₂ and 5% CO₂ and supplemented with 0.1% (w/v) bovine serum albumin to diminish non-specific adsorption of the toxins (Li et al., Biochemistry 33:7014-7020 (1994)). The hemidiaphragms are kept in a bath containing 10 ml Krebs-Ringer buffer at 37° C. for 10 minutes before being exposed to 4 or 10 nM native TeNT (▾ and ∇, respectively) or 10 nM nicked recombinant TeNT () or 10 nM un-nicked recombinant TeNT (◯), respectively. (See FIG. 4).

Muscle twitch is evoked by supra-maximal stimulation of the phrenic nerve with bipolar electrodes and recorded via a force-displacement transducer (Lectromed, UK) connected to an amplifier and computer system (MacLab, AD Instruments, UK). Parameters of nerve stimulation are 0.2 Hz square waves of 0.1 msec duration with 1.5-2.5 V amplitude. Toxin-induced paralysis of neuromuscular transmission is quantified as the time required for nerve-evoked muscle contraction to decrease to 10% (90% reduction) of the original value.

As shown in FIG. 4, 10 nM recombinant nicked TeNT was found to be as potent as 10 nM native toxin in blocking nerve-induced muscle twitch, with the preparations yielding a 90% reduction in muscle tension in approximately 170 minutes. Thus, this novel preparation of TeNT expressed in E. coli at high level as a single-chain, activatable polypeptide and purified by a simple affinity chromatography step proved to be fully active by all the criteria examined.

By contrast, 10 nM of the unnicked TeNT preparation require approximately twice as long to reduce muscle tension, and was approximately as active as 4 nM of the wild-type TeNT. As a control, hemidiaphragms incubated with KR buffer and the trace amount of enterokinase present in the experimental samples were found to show negligible decrease in muscle tension over 5 hrs.

Thus, this experiment indicates that the unnicked TeNT is considerably less toxic that either the wild type or recombinant nicked protein in vitro.

Example 5 Further Modification of Single-Chain TeNT to Remove Proteolytic Cleavage Sites Reduces Toxicity of Unnicked Recombinant Toxin

While the unnicked recombinant single-chain form of TeNT displays reduced toxicity as compared to the nicked form, the residual toxin activity probably arises from activation of the toxin by additional proteases in vivo. To test this possibility, sites in the single-chain toxin molecule susceptible to proteolytic cleavage by trypsin and Arg C protease are identified by incubation of single-chain TeNT with these enzymes as follows. Fifty micrograms μg of recombinant single-chain TeNT is incubated with 4 μg of Arg-C at 37° C. for 4 h; 0.1 μg of trypsin at 37° C. for 0.5 h; or buffer without protease as a control. These reactions are terminated by the addition of SDS-PAGE sample buffer containing 0.1% SDS followed by boiling for 5 minutes; then the samples are subjected to SDS-PAGE, followed by a Western electrophoretic transfer to a polyvinylidenedifluoride (PVDF) membrane. The membrane is blotted with IgG specific for the His₆-tag and detected using a horseradish peroxidase staining system.

As shown in FIG. 5, the Western blot reveals that trypsin and Arg C protease yielded a L chain (and thus a H chain) fragment of the same size. Additionally, the transfer of a duplicate gel was stained for protein with Ponceau red and the H chain band of approximate molecular weight 100 kDa was excised from each lane and analysed by N-terminal sequencing.

In the recombinant single-chain TeNT, the LC and HC are linked by 17 amino acids (GEKLYDDDDKDRWGSSR), followed by the beginning of the H chain sequence (SLTDLGGEL . . . ). N-terminal amino acid sequencing of the larger fragment produced by both trypsin and Arg C protease reveal that first 5 amino acids of the 100 kDa trypsin and Arg C protease cleavage product protein are SLTDL; thus, these proteases appear to cleave the single-chain toxin between the R—S bond (see FIG. 1) so as to liberate the H chain and the L chain containing the EK linker at its C terminus, with this variant therefore yielding a di-chain toxin essentially identical to the EK nicked toxin.

The arginine at the carboxy terminus of the EK linker sequence is mutated by site-directed mutagenesis to a glycine (R496G), and the resulting single-chain toxin polypeptide is expressed and purified as above.

Titration of the 6 micrograms of the R496G mutated single-chain (WT LC) toxin and the SC TeNT lacking such a mutation against 0, 0.01, 0.1, 1, 10 μg/ml of trypsin, followed by SDS-PAGE and staining with Coomassie Brilliant Blue, yields the cleavage pattern seen in FIG. 6. As can be seen, both single-chain molecules are susceptible to typsin cleavage; however the R496G mutant yields fewer fragments than the SC toxin not containing a mutation in the loop region between the chains. For example, while three trypsin peptide bands can clearly be seen near the light chain band upon trypsin cleavage of the SC WT toxin, only two such bands are seen in the R496G digests.

The fact that there exist remaining trypsin sites in the R496G mutant SC toxin probably accounts for the fact that this mutant does not cause the lowering of toxicity as compared to the un-nicked SC toxin; both preparations give similar values in the mouse lethality and neuromuscular paralysis assays described above.

A different assay system is used to measure neurotoxin activity toward CNS neurons, the cells naturally affected by TeNT. The cells used are cerebellar neurons; these cells are disassociated from the cerebella of 7 day old rats. Neurons are suspended at 1-2×10⁶/mL in medium consisting of 3 parts Basal Eagle Medium and 1 part of a buffer consisting of 40 mM HEPES-NaOH (pH 7.3), 78.4 mM KCl, 37.6 mM D-glucose, 2.8 mM CaCl₂, 1.6 mM MgSO₄ and 1.0 mM NaH₂PO₄, as well as 1×N2 supplement, 1.0 mM L-glutamine, 60 units/mL penicillin, 60 μg/mL streptomycin and 5% (v/v) dialysed horse serum. One milliliter of this cell suspension is added to 22 mm diameter poly-D-lysine coated wells. Cytosine β-D-arabinofuranoside (Ara-C, 40 μM) is added after 20-24 hours in 5% (v/v) CO₂ culture, and neurons are maintained by weekly replacement of the above-noted medium containing 40 μM Ara-C.

For each assay, neurons are cultured for at least 10 days in vitro are washed four times with O₂-gassed Krebs-Ringer HEPES buffer (KRH, mM: 20 HEPES.NaOH pH7.4, 128 NaCl, 5 KCl, 1 NaH₂PO₄, 1.4 CaCl₂, 1.2 mM MgSO₄, 10 D-glucose and 0.05 mg/mL BSA), and 0.5 mL of the latter buffer containing 0.25 μCi/mL [14C]-glutamine (i.e. the glutamate precursor) is added. All steps are performed at 37° C. After a 45 minute labeling period, the medium is removed and the neurons washed four times as before. Control and toxin-treated neurons are incubated for 5 minutes at 37° C. in KRH buffer containing either 1.4 mM Ca²⁺ or 0.5 mM EGTA (i.e. to assess C²⁺-independent release); aliquots are then removed and retained for assessment of [¹⁴C]-glutamate content by scintillation counting. Immediately after removal of the above basal medium, a modified KRH buffer containing 50 mM KCl (containing a lowered 83 mM NaCl content in order to maintain a normal osmotic potential) and either 1.4 Ca²⁺ or 0.5 mM EGTA are added for a 5 minute stimulation period. Finally, neurons were solubilized with 20 mM EGTA.NaOH pH 7.5 containing 1% (w/v) SDS, and aliquots subjected to scintillation counting in order to calculate their remaining radioactive contents. The amounts of ¹⁴C-glutamate in basal and stimulated samples are expressed as percentages relative to the calculated total cell content. The percentage [¹⁴C]-glutamate contents in EGTA-containing buffer are subtracted from the values recorded in C²⁺-containing samples in order to calculate the relevant Ca²⁺-dependent component of release and in turn the latter basal readings are subtracted from values obtained for 50 mM KCl samples to yield the K⁺-evoked Ca²⁺-dependent glutamate release component.

FIG. 8 demonstrates the ability of the recombinant toxin to inhibit neurotransmitter release. Cerebellar neurons, maintained for 10 days in vitro, were washed twice with ice-cold KRH buffer containing 5 mM Mg²⁺ and 0.5 mM Ca²⁺, then exposed in this buffer to the specified concentrations of () native TeNT, (◯) EK-nicked TeNT R496G, (▾) single-chain unnicked TeNT, or (∇) EK-nicked TeNT E234A for 60 min at 4° C. (see FIG. 8). Native TeNT (0.2 nM) was then added to the wells specified and, after an additional 30 min, the neurons were washed three times with ice-cold KRH buffer and incubated for 30 min at 37° C. Subsequent assessment of K⁺-evoked Ca²⁺-dependent neurotransmitter release was performed as detailed above. The results of this assay are shown in FIG. 8.

When cerebellar neurons are exposed to nicked recombinant TeNT, a dose-dependent inhibition of Ca⁺⁺ dependent transmitter release is seen with a potency similar to the native toxin. Nicked recombinant SC TeNT, both WT and R496G, gave similar values in this assay. Thus, while toxin activity in the unnicked single-chain molecule is not abrogated through the removal of a single trypsin cleavage site, the removal of additional such sites is feasible in regions of the single-chain toxin to achieve an activatable single-chain proform of the toxin that exhibits even lower toxicity unless activated in vitro, when its full activity can be achieved.

Example 7 Protease-Deficient TeNT Mutant Antagonises the Actions of TeNT on Peripheral and Central Neurons

Table 3 shows the tabulated results of the indicated TeNT constructs tested in three assays of toxin activity: ability to cleave the HV62 peptide (which measures proteolytic activity only); neuromuscular paralysis (which is an indication of the toxin molecules' ability to enter the cell and thence to inhibit neurotransmitter release), and mouse lethality upon intraperitoneal injection of the various toxin constructs. The first two of these assays was performed as described above.

The mouse lethality assay was performed essentially as follows: Samples of recombinant purified single-chain TeNT, R496G mutant TeNT, and E234A mutant TeNT are each divided into two aliquots and one aliquot treated with enterokinase to nick the toxin. All samples are serially diluted into 50 mM phosphate buffer (pH 7.0), 150 mM NaCl and 0.25% (w/v) bovine serum albumin (BSA), and the toxin preparations are injected into mice intraperitoneally.

As shown in Table 3, the native and nicked TeNT preparations were comparably active in the mouse lethality assay, having an LD₅₀ of about 1×10⁸/mg. The unnicked recombinant toxin and unnicked R496G mutant were both about half as active. Finally, the nicked E234A proteolytically inactive toxin was less than 5×10⁷ fold less active.

TABLE 3 Biological Activity of SC TeNT wild type and mutants (E234A and R496G) before and after nicking with enterokinase Time (min.) for 10 nM Initial rate of cleavage^(a) of to cause 90% Purified TeNT HV62 (nmol. min⁻¹mg⁻¹) Mouse lethality^(b) neuromuscular preparations [Relative rate (%)] (LD50/mg) paralysis Native 20.3 ± 0.91 1 × 10⁸ 145 Un-nicked SC WT  8.0 ± 0.03 0.5 × 10⁸   260 Nicked^(c) SC WT 22.7 ± 3.37 1 × 10⁸ 150 Un-nicked SC R496G 11.7 ± 0.6  0.5 × 10⁸   250 ± 15 Nicked^(c) SC R496G 52.3 ± 4.9  1 × 10⁸ 135 ± 10 Un-nicked SC E234A ≦0.01^(d) Not tested Not tested Nicked^(c) SC E234A ≦0.01^(d) <50 No detectable activity ^(a)Initial rates of proteolysis were measured using the RP-HPLC-based method detailed in Foran et al. (1994). Incubations with 15 μM of a synthetic peptide corresponding to residues 33 to 94 of human VAMP-2 (HV62) were performed at 37° C. in 50 mM HEPES, NaOH pH 7.5 containing 2 mM DTT 0.2 mg · ml⁻¹ BSA and 50 μM ZnCl₂, using the appropriate concentration of each reduced toxin preparation required to proteolyze 10-15% of the substrate during a 30 min period. Data are means (±S.D.; n = 4). ^(b)LD₅₀ is the amount of toxin that killed 50% of the injected mice within 4 days. ^(c)Toxin preparations were nicked with EK (1 unit/30 μg) at 22° C. for 1 h. ^(d)This v° value represents the detection limits of the RP-HPLC assay; no proteolysis of HV62 was observed using prolonged incubations.

Purified SC E234A TeNT, in which the catalytic E at position 234 was replaced by an A, failed to show any detectable proteolysis of a peptide containing residues 33 to 94 of human VAMP-2 (termed HV62), either before or after nicking with EK. Accordingly, nicked TeNT E234A proved to be devoid of toxicity in mice and unable to inhibit transmitter release at the neuromuscular junction or from cerebellar neurons.

Importantly, however, this mutant toxin retained the ability to bind to the cell surface receptors on peripheral and central neurons. Pre-incubation of cerebellar neurons with nicked (10-60 nM) or unnicked (7-40 nM) TeNT E234A at 4° C. followed by the addition of 0.2 nM native toxin, antagonized the native toxin's inhibition of transmitter release at 37° C. to similar extents (FIG. 7).

As demonstrated in FIG. 9, exposure of mouse diaphragm to 100 nM TeNT E234A at 4° C. for 60 minutes prior to adding 1 nM native toxin prolonged the time taken to cause neuromuscular paralysis.

Mouse phrenic-nerve hemi-diaphragm was incubated in KR at 37° C. with 20 nM recombinant TeNT E234A (Δ) whilst stimulating the nerve (0.2 Hz, 1.5-2.5 v) and recording muscle tension. For assessing competition, hemi-diaphragms were incubated for 60 minutes at 4° C. with MKR containing 0.1% BSA only (□), or the latter plus 100 nM nicked TeNT E234A (◯), before the addition of 1 nM native TeNT. Following 30 minutes exposure to the latter, the tissues were washed three times with MKR and twice with KR. The temperature was raised to 37° C. and the nerve stimulated with recording of the evoked muscle twitch, as outlined above. This apparent competition for toxin binding by the mutant seen with both tissues demonstrates that the recombinant di-chain TeNT exhibits much higher affinity for the cell surface receptors than the heavy chain or H, of TeNT alone. These results suggest that the conformation of the recombinant di-chain TeNT has high affinity to the cell surface receptor.

Moreover, and very significantly, these data demonstrate that recombinant molecules can be made according to the inventive methods of the present patent application having specific binding for the same cellular receptor as TeNT. However, such molecules may, like the E234A mutant, be inactive as toxin molecules but will retain the ability to be taken up by the target cell; thus serving as potential transporter molecules.

Example 8 Expression of Single-Chain BoNT/A

Using methods similar to those described above, DNA fragments containing the BoNT subtype A neurotoxin H and L chains were ligated together, separated by the EK cleavage site. This single-chain toxin coding sequence was inserted into a variety of expression vectors containing different N terminal sequences and promoters, as shown in Table 4, below.

TABLE 4 Tag Size Fusion (amino Size E. coli Vector Promoter Fusion Tag acids) (kDa) strain pTrcSCPHY trc Poly His 18 150 JM109 pCalSCPHY T7 Calmodulin 31 154 BL21 binding (DE3) protein pETSCPHY T7 Poly His 32 154 BL21 (DE3) pGEXSCPHY tac Glutathione- 224 177 JM109 S-tranferase pMALPHY tac Maltose 390 193 JM109 Binding Protein

The “fusion tags” each comprised a member of a specific binding complex as a purification aid and to improve the solubility and stability of the expressed protein. These plasmids were transformed into the E. coli strains indicated in Table 4 and expression of the single-chain toxin was monitored.

In another experiment, the single-chain BoNT/A construct was inserted into plasmid pMAL-c2 between the Bam HI and Hind III restriction sites, resulting in a coding sequence for a fusion polypeptide containing the maltose binding protein at the N terminus, followed by a Factor Xa cleavage site. Transformant JM 109 colonies were selected in Luria broth containing ampicillin. Expression was induced by the addition of IPTG to a final concentration of 0.3 mM. As for the TeNT construct, aliquots of the cell culture were collected before and after induction, the cells in each sample lysed by sonication, and the supernatant prepared for SDS-PAGE under both reducing and non-reducing conditions. Following electrophoresis to separate the proteins according to apparent molecular weight, the gel was subjected to a Western blot using an antibody raised against the H chain of BoNT/A. The Western blot resulted in the appearance of an immunologically reactive single-chain toxin band of apparent molecular weight approximately 200 kDa. Further modifications of the single-chain BoNT molecule to eliminate fortuitous protease cleavage sites (similar to those modifications made at the TeNT site labile to trypsin and Arg C protease, described above) will result in even greater stability of the single-chain BoNT/A molecule.

Example 9 Construction of a Plasmid Vector Expressing BoNT/E

A plasmid expressing a single-chain recombinant version of the neurotoxin from Clostridium botulinum subtype E (strain Beluga) (BoNT/E) was constructed as follows. PCR primers were designed based on the EMBL database cDNA sequence of the BoNT/E neurotoxin (Genbank accession number X62089) This nucleotide sequence is represented herein as SEQ ID NO: 120.

gaattcaagt agtagataat aaaaataatg ccacagattt ttattattaa taatgatata tttatctcta actgtttaac tttaacttat aacaatgtaa atatatattt gtctataaaa aatcaagatt acaattgggt tatatgtgat cttaatcatg atataccaaa aaagtcatat ctatggatat taaaaaatat ataaatttaa aattaggaga tgctgtatat gccaaaaatt aatagtttta attataatga tcctgttaat gatagaacaa ttttatatat taaaccaggc ggttgtcaag aattttataa atcatttaat attatgaaaa atatttggat aattccagag agaaatgtaa ttggtacaac cccccaagat tttcatccgc ctacttcatt aaaaaatgga gatagtagtt attatgaccc taattattta caaagtgatg aagaaaagga tagattttta aaaatagtca caaaaatatt taatagaata aataataatc tttcaggagg gattttatta gaagaactgt caaaagctaa tccatattta gggaatgata atactccaga taatcaattc catattggtg atgcatcagc agttgagatt aaattctcaa atggtagcca agacatacta ttacctaatg ttattataat gggagcagag cctgatttat ttgaaactaa cagttccaat atttctctaa gaaataatta tatgccaagc aatcaccgtt ttggatcaat agctatagta acattctcac ctgaatattc ttttagattt aatgataatt gtatgaatga atttattcaa gatcctgctc ttacattaat gcatgaatta atacattcat tacatggact atatggggct aaagggatta ctacaaagta tactataaca caaaaacaaa atcccctaat aacaaatata agaggtacaa atattgaaga attcttaact tttggaggta ctgatttaaa cattattact agtgctcagt ccaatgatat ctatactaat cttctagctg attataaaaa aatagcgtct aaacttagca aagtacaagt atctaatcca ctacttaatc cttataaaga tgtttttgaa gcaaagtatg gattagataa agatgctagc ggaatttatt cggtaaatat aaacaaattt aatgatattt ttaaaaaatt atacagcttt acggaatttg atttacgaac taaatttcaa gttaaatgta ggcaaactta tattggacag tataaatact tcaaactttc aaacttgtta aatgattcta tttataatat atcagaaggc tataatataa ataatttaaa ggtaaatttt agaggacaga atgcaaattt aaatcctaga attattacac caattacagg tagaggacta gtaaaaaaaa tcattagatt ttgtaaaaat attgtttctg taaaaggcat aaggaaatca atatgtatcg aaataaataa tggtgagtta ttttttgtgg cttccgagaa tagttataat gatgataata taaatactcc taaagaaatt gacgatacag taacttcaaa taataattat gaaaatgatt tagatcaggt tattttaaat tttaatagtg aatcagcacc tggactttca gatgaaaaat taaatttaac tatccaaaat gatgcttata taccaaaata tgattctaat ggaacaagtg atatagaaca acatgatgtt aatgaactta atgtattttt ctatttagat gcacagaaag tgcccgaagg tgaaaataat gtcaatctca cctcttcaat tgatacagca ttattagaac aacctaaaat atatacattt ttttcatcag aatttattaa taatgtcaat aaacctgtgc aagcagcatt atttgtaagc tggatacaac aagtgttagt agattttact actgaagcta accaaaaaag tactgttgat aaaattgcag atatttctat agttgttcca tatataggtc ttgctttaaa tataggaaat gaagcacaaa aaggaaattt taaagatgca cttgaattat taggagcagg tattttatta gaatttgaac ccgagctttt aattcctaca attttagtat tcacgataaa atctttttta ggttcatctg ataataaaaa taaagttatt aaagcaataa ataatgcatt gaaagaaaga gatgaaaaat ggaaagaagt atatagtttt atagtatcga attggatgac taaaattaat acacaattta ataaaagaaa agaacaaatg tatcaagctt tacaaaatca agtaaatgca attaaaacaa taatagaatc taagtataat agttatactt tagaggaaaa aaatgagctt acaaataaat atgatattaa gcaaatagaa aatgaactta atcaaaaggt ttctatagca atgaataata tagacaggtt cttaactgaa agttctatat cctatttaat gaaaataata aatgaagtaa aaattaataa attaagagaa tatgatgaga atgtcaaaac gtatttattg aattatatta tacaacatgg atcaatcttg ggagagagtc agcaagaact aaattctatg gtaactgata ccctaaataa tagtattcct tttaagcttt cttcttatac agatgataaa attttaattt catattttaa taaattcttt aagagaatta aaagtagttc agttttaaat atgagatata aaaatgataa atacgtagat acttcaggat atgattcaaa tataaatatt aatggagatg tatataaata tccaactaat aaaaatcaat ttggaatata taatgataaa cttagtgaag ttaatatatc tcaaaatgat tacattatat atgataataa atataaaaat tttagtatta gtttttgggt aagaattcct aactatgata ataagatagt aaatgttaat aatgaataca ctataataaa ttgtatgaga gataataatt caggatggaa agtatctctt aatcataatg aaataatttg gacattcgaa gataatcgag gaattaatca aaaattagca tttaactatg gtaacgcaaa tggtatttct gattatataa ataagtggat ttttgtaact ataactaatg atagattagg agattctaaa ctttatatta atggaaattt aatagatcaa aaatcaattt taaatttagg taatattcat gttagtgaca atatattatt taaaatagtt aattgtagtt atacaagata tattggtatt agatatttta atatttttga taaagaatta gatgaaacag aaattcaaac tttatatagc aatgaaccta atacaaatat tttgaaggat ttttggggaa attatttgct ttatgacaaa gaatactatt tattaaatgt gttaaaacca aataacttta ttgataggag aaaagattct actttaagca ttaataatat aagaagcact attcttttag ctaatagatt atatagtgga ataaaagtta aaatacaaag agttaataat agtagtacta acgataatct tgttagaaag aatgatcagg tatatattaa ttttgtagcc agcaaaactc acttatttcc attatatgct gatacagcta ccacaaataa agagaaaaca ataaaaatat catcatctgg caatagattt aatcaagtag tagttatgaa ttcagtagga aattgtacaa tgaattttaa aaataataat ggaaataata ttgggttgtt aggtttcaag gcagatactg tcgttgctag tacttggtat tatacacata tgagagatca tacaaacagc aatggatgtt tttggaactt tatttctgaa gaacatggat ggcaagaaaa ataaaaatta gattaaacgg ctaaagtcat aaattc

The forward primer had the following nucleotide base sequence:

(SEQ ID NO: 121) CCCGGATCC CCA AAA ATT AAT AGT TTT AAT TAT AAT G

where the BamHI endonuclease site is underlined and the sequence of the light chain minus the start codon is in bold. The inverse primer had the sequence:

(SEQ ID NO: 122) CCCCTGCAG tca TTT TTC TTG CCA TCC ATG TTC TTC

where the PstI endonuclease site is underlined, the end of the coding region of the heavy chain is in bold, and the stop codon is in lower case. These primers were made using standard DNA synthesis methodology.

The two primers were used in a PCR reaction containing different amounts of Clostridium botulinum type E (strain beluga) chromosomal DNA. The PCR reaction employed a DNA polymerase with proofreading activity (Pfx DNA polymerase, obtained from Life Technology) in order to avoid sequence errors in the amplified gene. The amplification reaction conditions were as follows: 30 cycles of: a 45 second denaturation at 95° C., followed by a 45 second annealing step at 56° C., followed by a primer extension reaction for 3 minutes 48 seconds at 68° C.

The PCR product was digested with BamHI and HindIII, and the digest subjected to agarose gel electrophoresis. Staining of the agarose gel with ethidium bromide revealed a major DNA fragment of approximately 3.5 kilobases (see FIG. 10). The band containing this fragment was excised from the gel, and the DNA purified from the agarose and ligated to BamHI and HindIII-cut pQE30 vector (Qiagen). The resulting ligated plasmid was used to transform E. coli strain JM 109 as described above, and the transformants plated onto selective LB agar plates. Several clones were recovered and the presence of the correct BoNT/E DNA insert checked by restriction digest. The resultant construct contains the BoNT/E gene (minus the first methionine) fused to the His₆ tag of the pQE30 vector, and contains 2 extra amino acid residues (glycine, serine), which are contributed by the engineered BamHI site.

Example 10 Construction of a Proteolytically-Inactive Mutant of BoNT/E by Site Directed Mutagenesis

By mutating the glutamic acid at position 212 (within the active site) of the BoNT/E polypeptide construct to glutamine, a proteolytically-inactive and non-toxic single-chain BoNT/E polypeptide was obtained.

The glutamine replacement was introduced on the forward primer using routine site directed mutagenesis methods. The mutagenic DNA primer had the sequence cagTTAATACATTCATTA CATGGACTATATG (SEQ ID NO: 123), where the codon encoding glutamine at position 212 is indicated in small letters. An inverse PCR reaction was performed using the above primer, along with the reverse primer ATGCATTAATGTAAGAGCAGGATCTT (SEQ ID NO: 124) and Pfx DNA polymerase (Life Technology) as above. The PCR template was the wild-type single-chain BoNT/E construct (termed pQEESCwt). The cycling parameters (30 cycles) were as follows: 1) a 45 second denaturation step at 95° C.; 2) a 45 second annealing step at 56° C.; and 3) a 7 minute 10 second extension step at 68° C.

At the end of the amplification reaction, the DNA template was digested by the restriction enzyme DpnI to permit selection of mutated clones only. After subjecting the PCR product to agarose gel electrophoresis, a band of approximately 7 kilobases was removed and the DNA purified and used for self-ligation in the presence of T4 DNA ligase (Promega) and polynucleotide kinase (Promega) to permit phosphorylation of the PCR product. The ligation mixture was used to transform E. coli strain DH10B, and the transformants plated onto selective agar plates. The presence of the correct plasmid construct was verified in several representative transformants by restriction digest and the mutation confirmed also by DNA sequencing. FIG. 11 shows the protocol for construction of the mutant BoNT/E plasmid, and an ethidium bromide-stained agarose gel of the PCR reaction mixture (lanes 2 and 3) versus molecular weight markers (lane 1).

Example 11 Purification of Single-Chain Recombinant BoNT/E

The presence of the histidine tag at the N-terminus of the expressed protein allowed a single-step purification of the recombinant neurotoxin by metal-affinity chromatography.

The E. coli strain M15 (Qiagen) was used for expression of the BoNT/E single-chain construct. This strain carries an endogenous plasmid (pREP4, kanamycin resistant) containing a region encoding the lac I^(q) repressor gene in order to prevent transcription of the neurotoxin gene prior to induction with IPTG. The pQE30 vector contain a T5 bacteriophage RNA polymerase promoter, which is also recognized by E. coli RNA polymerase.

A colony of M15 cells containing pQEESCwt was grown at 37° C. overnight in 5 ml of 2TY medium containing 0.1 mg/ml ampicillin; 0.025 mg/ml kanamycin and 0.2% glucose (w/v), and the resultant culture used to inoculate 500 ml of the same medium. When this second culture reached an optical density of 0.5-0.8 at 600 nm, IPTG was added to a final concentration of 0.3 mM and the culture incubated at 25° C. overnight to permit expression of the neurotoxin.

Subsequent centrifugation of the culture yielded ˜2.3 g of wet cell pellet which was resuspended in 10 ml of extraction buffer (20 mM Hepes pH 7.0, 300 mM NaCl, 5 mM benzamidine, 2 μM pepstatin and 2 μM E-64). Lysozyme was added to a final concentration of 0.25 mg/ml, and the cell suspension incubated on ice for 60 minutes. Approximately 0.5 ml of glass beads (0.1 mm diameter from Biospec) was added to the cell suspension, followed by vortexing for 2 minutes to break the cells. Cell-free extracts was obtained by centrifugation at 10,000×g for 30 minutes at 4° C. The supernatant was incubated with 0.5 ml of Talone cobalt metal affinity resin (Clontech) pre-washed with extraction buffer in a rocking platform for 45 minutes at 4° C. The resin was then loaded into a disposable chromatography column and washed twice with 10 bed volumes of wash buffer (20 mM Hepes pH 7.0, 300 mM NaCl, 2 mM imidazole) before eluting the bound neurotoxin in 6 bed volumes of elution buffer (20 mM Hepes pH 7.0, 300 mM NaCl, 150 mM imidazole).

The elute was dialyzed overnight at 4° C. against 10 mM Hepes (pH 7.0) containing 150 mM NaCl and concentrated by centrifugal filtration (MW cutoff 10 KDa) to a final concentration of 1 mg/ml protein.

As shown in FIG. 12, the purity of the affinity-purified toxin was demonstrated by SDS-PAGE under reducing conditions, followed by Coomassie staining and Western-blotting, detecting the N-terminus with a mouse monoclonal anti-His antibody from Quiagen (diluted 2000 fold). Enhanced Chemiluminescence solutions (Santa Cruz) and mouse secondary horseradish peroxidase (affinity purified from Sigma) were used for detection of bound antibody. Approximately 2 μg of protein samples were loaded per well.

Example 12 Trypsin Activation of Purified Recombinant BoNT/E Single-Chain Polypeptide

Purified BoNT/E single-chain neurotoxin polypeptide samples were activated by nicking the single-chain with trypsin (1.5 μg/ml final concentration) for 60 minutes at a concentration of 1 mg toxin/ml in 10 mm Hepes (pH 7.0), 150 mM NaCl. Following the reaction, the trypsin was inactivated using 0.5 mM PMSF and 10 μg trypsin inhibitor/ml. The quality of the trypsinization was assessed and verified by SDS-PAGE under both reducing and non-reducing conditions, then staining with Coomassie staining and Western blotting the polyacrylamide gel using a mouse monoclonal anti-His antibody (Quiagen, diluted 2000-fold) and a mouse monoclonal anti-H_(C) IgG (diluted 26-fold). As shown in FIG. 13, the Commassie-stained nicked protein resolves into two bands under reducing conditions, while the heavy and light chains remain disulfide-linked under non-reducing conditions, similar to the native toxin. The antibody-detected recombinant heavy chain is of approximately identical size as its wild-type Clostridium counterpart, whereas the recombinant light chain migrates at a slightly higher molecular weight compared to the native protein. This latter characteristic is due to the extra residues provided by the His₆ tag at the N-terminus.

Example 13 Recombinant BoNT/E is Proteolytically Active

Stock solutions (1 μM) of native nicked BoNT/E toxin, un-nicked single-chain recombinant toxin, nicked di-chain recombinant toxin, and nicked mutant (E212Q) BoNT/E were prepared in HEPES-buffered saline (HBS, 150 mM NaCl, 10 mM HEPES, pH 7.4, 10 μg/ml BSA). These samples were incubated for 30 minutes at 37° C. in the absence or presence of 20 mM DTT, and then serially diluted in 0.02 ml of HBS to the final concentrations shown in FIG. 14.

A recombinant peptide containing amino acids 140-205 of SNAP-25 fused to glutathione-S-transferase (termed GST-SNAP-25 [140-205]) was used as a protease substrate to test the proteolytic activity of the recombinant BoNT/E polypeptides. Ten micrograms this protease substrate was incubated with the toxin samples. The digestion reaction was allowed to proceed for 30 minutes at 37° C. in the absence or presence of 2 mM DTT, and stopped by addition of SDS-PAGE sample buffer followed by boiling for 5 minutes.

The resultant samples were analyzed by SDS-PAGE (3 μg of GST-SNAP-25 [140-205] per lane) and silver staining. As FIG. 14 demonstrates, even unnicked recombinant single-chain toxin retains proteolytic activity. As expected, the mutant E212Q BoNT/E construct has no detectable proteolytic activity. FIG. 14 shows only the GST-SNAP-25[140-205] bands.

Example 14

Nicking Makes Recombinant BoNT/E Fully Functional

Cerebellar neurons maintained for 10 days in culture (2×10⁶/22 mm diameter well) were washed with Krebs-Ringer HEPES (KRH) buffer, then exposed to the specified concentrations of BoNT/E native (), trypsin-nicked recombinant (◯), or un-nicked single-chain (▾) BoNT/E. (See FIG. 15). After 60 minutes at 37° C., the toxin-containing buffer was removed and the cells were washed twice, then incubated with KRH buffer containing 0.25 μCi/ml [¹⁴C]-labeled glutamine (i.e. the glutamate precursor). After 45 minutes, the latter medium was removed and the neurons were washed four times at 37° C. prior to assessment of transmitter glutamate release. Control and toxin-treated neurons were incubated for 5 minutes at 37° C. in KRH buffer containing either 1.4 mM Ca²⁺ or 0.5 mM EGTA to assess Ca²⁺-independent release; aliquots were then removed for determination of their [¹⁴C]-glutamate content (see below).

Immediately after removal of the basal medium, KRH buffer containing 50 mM KCl and either 1.4 mM Ca²⁺ or 0.5 mM EGTA was added; as before, aliquots were removed for [¹⁴C]-glutamate assay after a 5 minute stimulation period. Finally, neurons were solubilized with 20 mM EGTA.NaOH pH 7.5 containing 1% (w/v) SDS and aliquots were removed to determine the amounts of radioactivity remaining within the cells. The amount of [¹⁴C]-glutamate in each of the samples was assayed by scintillation counting and the levels released under basal and stimulated conditions were expressed as percentages relative to the calculated total cell content.

The percent [¹⁴C]-glutamate content in the EGTA-containing buffer for each sample was subtracted from the values recorded in Ca²⁺-containing KRH samples in order to obtain the Ca²⁺-dependent component of release, and the latter basal readings were subtracted from values obtained for 50 mM KCl samples to yield K⁺-evoked Ca²⁺-dependent release. The values, thus, obtained from toxin-treated neurons are expressed relative to toxin-free controls.

FIG. 15 shows that, despite retaining proteolytic activity, the un-nicked recombinant BoNT/E has markedly less activity than either the native BoNT/E or the nicked recombinant version. This finding may reflect the inability of the un-nicked toxin to adequately enter the target cell. Additionally, the nicked recombinant version appears to be more effective in inhibiting glutamate release than the native toxin.

Example 15 Recombinant BoNT/E has a Neuromuscular Paralytic Activity Equivalent to that of the Native Toxin at Mouse Neuromuscular Endplates: Nicking Increases Potency

Mouse phrenic-nerve hemi-diaphragms were bathed in KR supplemented with 0.1% BSA and saturated with 95% O₂/5% CO₂. The phrenic nerves were stimulated (0.2 Hz, 1.5-2.5 mV) and nerve evoked muscle tension was recorded before and after the addition of (FIG. 16A) 0.2 nM recombinant nicked BoNT/E (◯) or 0.2 nM native BoNT/E (□), and (FIG. 16B) 1 nM recombinant un-nicked (◯), 1 nM recombinant nicked () or 0.05 nM recombinant nicked (∇) BoNT/E. As shown in FIGS. 16A and 16B, the recombinant nicked BoNT/E is an effective paralytic agent, displaying greater activity in this assay that the native toxin. The un-nicked toxin displays significantly lower activity than the nicked toxin in this assay.

The neuromuscular paralytic activity of recombinant nicked BoNT/E was also demonstrated in mice by intra-muscular injection into hind-limb muscles. This resulted in paralysis, as assessed by the toe spread reflex assay, with a pattern of symptoms typical of botulism.

The in vivo neurotoxicity of the nicked, recombinant neurotoxin was established, by injecting the toxin into mice, to have a specific neurotoxicity of less than 10⁷ mouse LD₅₀ units per mg.

Example 16 The BoNT/E E212Q Protease Inactive Mutant Antagonises BoNT/E-Induced Neuroparalysis

A mouse phrenic-nerve hemi-diaphragm was exposed to 10 nM BoNT/E E212Q in KR medium, the nerve was stimulated and evoked muscle tension was recorded. As indicated by FIG. 17, the BoNT E212Q mutant does not inhibit neurotransmission, as determined by its failure to reduce nerve-evoked muscle tension (◯). To assess the ability of this non-toxic mutant to antagonise the activity of the native toxin, mouse phrenic-nerve hemi-diaphragms were bathed for 60 minutes at 4° C. in MKR supplemented with 0.1% BSA and saturated with 95% O₂/5% CO₂, without (□) or with (Δ) the inclusion of 5 nM BoNT/E E212Q. Native nicked BoNT/E was added to each bath (0.05 nM final) and the tissues were incubated for a further 30 min. The nerve-muscles were then washed three times each with MKR followed by KR, before the temperature was raised to 37° C., the nerve stimulated and evoked muscle tension recorded.

As shown in FIG. 17, the onset of native BoNT/E activity in this assay was delayed and antagonized when the phrenic-nerve hemi-diaphragms are preincubated with the E212Q protease inactive mutant, thereby indicating that the recombinant mutant faithfully binds to the same cell surface receptor as does the native toxin. Thus, the methods of the present patent application can be used to produce recombinant and modified toxins having fully functional receptor binding domains, and BoNT-related transported molecules for the intracellular delivery of therapeutic agents.

Example 17 Construction of an Activatable Clostridial Toxin Comprising an Amino-Terminally Presented Binding Element

This example illustrates how to make an activatable Clostridial toxin disclosed in the present specification comprising a binding element located at the amino terminus of the modified toxin.

17a. A Binding Element-Translocation Element-Exogenous Protease Cleavage Site-Therapeutic Element Organization.

A polynucleotide molecule based on BoNT/A-TEV-NociceptinAP4A (SEQ ID NO: 125) will be synthesized using standard procedures (BlueHeron® Biotechnology, Bothell, Wash.). This polynucleotide molecule encodes a BoNT/A modified to replace amino acids 872-1296 of SEQ ID NO: 1, a BoNT/A HC binding element, with SEQ ID NO: 101, a nociceptin-RK peptide and to incorporate a TEV protease site of SEQ ID NO: 24 within the di-chain loop region, arranged in an amino to carboxyl linear organization as depicted in FIG. 20A. The In addition, the altered binding element further comprises at its amino terminus, a PAR 1 leader sequence ending in an enterokinse cleavage site, which, upon cleavage, results in exposing the first amino acid of the nociceptin-RK binding element. Oligonucleotides of 20 to 50 bases in length are synthesized using standard phosphoramidite synthesis. These oligonucleotides will be hybridized into double stranded duplexes that are ligated together to assemble the full-length polynucleotide molecule. This polynucleotide molecule will be cloned using standard molecular biology methods into a pUCBHB1 vector at the SmaI site to generate pUCBHB1/BoNT/A-TEV-NociceptinAP4A. The synthesized polynucleotide molecule is verified by sequencing using Big Dye Terminator™ Chemistry 3.1 (Applied Biosystems, Foster City, Calif.) and an ABI 3100 sequencer (Applied Biosystems, Foster City, Calif.).

If desired, an expression optimized polynucleotide molecule based on BoNT/A-TEV-NociceptinAP4A can be synthesized in order to improve expression in an Escherichia coli strain. The polynucleotide molecule encoding the BoNT/A-TEV-NociceptinAP4A will be modified to 1) contain synonymous codons typically present in native polynucleotide molecules of an Escherichia coli strain; 2) contain a G+C content that more closely matches the average G+C content of native polynucleotide molecules found in an Escherichia coli strain; 3) reduce polymononucleotide regions found within the polynucleotide molecule; and/or 4) eliminate internal regulatory or structural sites found within the polynucleotide molecule, see, e.g., Lance E. Steward et al., Optimizing Expression of Active Botulinum Toxin Type E, International Patent Publication WO 2006/011966 (Feb. 2, 2006); Lance E. Steward et al., Optimizing Expression of Active Botulinum Toxin Type A, International Patent Publication WO 2006/017749 (Feb. 16, 2006). Once sequence optimization is complete, oligonucleotides of 20 to 50 bases in length are synthesized using standard phosphoramidite synthesis. These oligonucleotides are hybridized into double stranded duplexes that are ligated together to assemble the full-length polynucleotide molecule. This polynucleotide molecule is cloned using standard molecular biology methods into a pUCBHB1 vector at the SmaI site to generate pUCBHB1/BoNT/A-TEV-NociceptinAP4A. The synthesized polynucleotide molecule is verified by sequencing using Big Dye Terminator™ Chemistry 3.1 (Applied Biosystems, Foster City, Calif.) and an ABI 3100 sequencer (Applied Biosystems, Foster City, Calif.). If so desired, expression optimization to a different organism, such as, e.g., a yeast strain, an insect cell-line or a mammalian cell line, can be done, see, e.g., Steward, supra, (Feb. 2, 2006); and Steward, supra, (Feb. 16, 2006).

A similar cloning strategy will be used to make pUCBHB1 cloning constructs for BoNT/B-TEV-NociceptinAP4A, a modified BoNT/B where amino acids 861-1291 of SEQ ID NO: 2 are replaced with SEQ ID NO: 101; BoNT/C1-TEV-NociceptinAP4A, a modified BoNT/C1 where amino acids 869-1291 of SEQ ID NO: 3 are replaced with SEQ ID NO: 101; BoNT/D-TEV-NociceptinAP4A, a modified BoNT/D where amino acids 865-1276 of SEQ ID NO: 4 are replaced with SEQ ID NO: 101; BoNT/E-TEV-NociceptinAP4A, a modified BoNT/E where amino acids 848-1252 of SEQ ID NO: 5 are replaced with SEQ ID NO: 101; BoNT/F-TEV-NociceptinAP4A, a modified BoNT/F where amino acids 867-1274 of SEQ ID NO: 6 are replaced with SEQ ID NO: 101; BoNT/G-TEV-NociceptinAP4A, a modified BoNT/G where amino acids 866-1297 of SEQ ID NO: 7 are replaced with SEQ ID NO: 101; TeNT-TEV-NociceptinAP4A, a modified TeNT where amino acids 882-1315 of SEQ ID NO: 8 are replaced with SEQ ID NO: 101; BaNT-TEV-NociceptinAP4A, a modified BaNT where amino acids 858-1268 of SEQ ID NO: 9 are replaced with SEQ ID NO: 101; and BuNT-TEV-NociceptinAP4A, a modified BuNT where amino acids 848-1251 of SEQ ID NO: 10 are replaced with SEQ ID NO: 101.

Likewise, a similar cloning strategy will be used to make pUCBHB1 cloning constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-TEV-AP4A that will replace the HC binding element from a Clostridial toxin the with an binding element comprising, e.g, an enkephalin peptide comprising SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54, SEQ ID NO: 55; a BAM22 peptide comprising amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60 or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61; an endomorphin peptide comprising SEQ ID NO: 62 or SEQ ID NO: 63; an enkephalin comprising SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69; a dynorphin comprising SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 72, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80, SEQ ID NO: 81, SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 85, SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, SEQ ID NO: 90, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, SEQ ID NO: 94, SEQ ID NO: 95, SEQ ID NO: 96, SEQ ID NO: 97, SEQ ID NO: 98, SEQ ID NO: 99 or SEQ ID NO: 100; a nociceptin comprising SEQ ID NO: 102, SEQ ID NO: 103, SEQ ID NO: 104, SEQ ID NO: 105, SEQ ID NO: 106, SEQ ID NO: 107, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110.

Likewise, a similar cloning strategy will be used to make pUCBHB1 cloning constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin AP4A comprising an exogenous protease cleavage site incorporated within the di-chain loop region, e.g, a bovine enterokinase protease cleavage site comprising SEQ ID NO: 21; a TEV protease site comprising SEQ ID NO: 24, SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 or SEQ ID NO: 33; a a human rhinovirus 3C protease cleavage site comprising SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39 or SEQ ID NO: 40; a subtilisin cleavage site comprising SEQ ID NO: 43, SEQ ID NO: 44 or SEQ ID NO: 45; a hydroxylamine cleavage site comprising SEQ ID NO: 46 or SEQ ID NO: 47; and a SUMO/ULP-1 protease cleavage site comprising SEQ ID NO: 48.

To construct pET29/BoNT/A-TEV-NociceptinAP4A, a pUCBHB1/BoNT/A-TEV-NociceptinAP4A construct will be digested with restriction endonucleases that 1) will excise the polynucleotide molecule encoding the open reading frame of BoNT/A-TEV-NociceptinAP4A; and 2) will enable this polynucleotide molecule to be operably-linked to a pET29 vector (EMD Biosciences-Novagen, Madison, Wis.). This insert will be subcloned using a T4 DNA ligase procedure into a pET29 vector that is digested with appropriate restriction endonucleases to yield pET29/BoNT/A-TEV-NociceptinAP4A. The ligation mixture will be transformed into chemically competent E. coli DH5a cells (Invitrogen, Inc, Carlsbad, Calif.) using a heat shock method, will be plated on 1.5% Luria-Bertani agar plates (pH 7.0) containing 50 pg/mL of Kanamycin, and will be placed in a 37° C. incubator for overnight growth. Bacteria containing expression constructs will be identified as Kanamycin resistant colonies. Candidate constructs will be isolated using an alkaline lysis plasmid mini-preparation procedure and will be analyzed by restriction endonuclease digest mapping to determine the presence and orientation of the insert. This cloning strategy will yield a pET29 expression construct comprising the polynucleotide molecule encoding the BoNT/A-TEV-NociceptinAP4A operably-linked to a carboxyl terminal polyhistidine affinity binding peptide.

A similar cloning strategy will be used to make pET29 expression constructs for other modified Clostridial toxin-TEV-NociceptinAP4A toxins, such as, e.g., BoNT/B-TEV-NociceptinAP4A, BoNT/C₁-TEV-Nocicepti nAP4A, BoNT/D-TEV-NociceptinAP4A, BoNT/E-TEV-NociceptinAP4A, BoNT/F-TEV-NociceptinAP4A, BoNT/G-TEV-NociceptinAP4A TeNT-TEV-NociceptinAP4AB, BaNT-TEV-NociceptinAP4A, or BuNT-TEV-NociceptinAP4A. Likewise, a similar cloning strategy will be used to make pET29 expression constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-TEV-AP4B comprising a binding element such as, e.g, a binding element requiring a free amino-terminal amino acid like SEQ ID NO: 52 to SEQ ID NO: 100 or SEQ ID NO: 102 to SEQ ID NO: 110, as well as, amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60 or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61.

Furthermore, a similar cloning strategy will be used to make pET29 expression constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-AP4A comprising an exogenous protease cleavage site incorporated within the di-chain loop region such as, e.g, a bovine enterokinase protease cleavage site comprising SEQ ID NO: 21; a TEV protease site comprising SEQ ID NO: 24, SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 or SEQ ID NO: 33; a a human rhinovirus 3C protease cleavage site comprising SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39 or SEQ ID NO: 40; a subtilisin cleavage site comprising SEQ ID NO: 43, SEQ ID NO: 44 or SEQ ID NO: 45; a hydroxylamine cleavage site comprising SEQ ID NO: 46 or SEQ ID NO: 47; and a SUMO/ULP-1 protease cleavage site comprising SEQ ID NO: 48.

17b. A Binding Element-Therapeutic Element-Exogenous Protease Cleavage Site-Translocation Element Organization.

A polynucleotide molecule based on BoNT/A-TEV-NociceptinAP4B (SEQ ID NO: 126) will be synthesized and cloned into a pUCBHB1 vector as described in Example 17a. This polynucleotide molecule encodes a BoNT/A modified to replace amino acids 872-1296 of SEQ ID NO: 1, a BoNT/A HC binding element, with SEQ ID NO: 101, a nociceptin-RK peptide and to incorporate a TEV protease site of SEQ ID NO: 24 within the di-chain loop region, arranged in an amino to carboxyl linear organization as depicted in FIG. 20B. In addition, the altered binding element further comprises at its amino terminus, a PAR 1 leader sequence ending in an enterokinse cleavage site, which upon cleavage, results in exposing the first amino acid of the nociceptin-RK binding element. If so desired, expression optimization to a different organism, such as, e.g., a bacteria, a yeast strain, an insect cell-line or a mammalian cell line, can be done as described above, see, e.g., Steward, supra, (Feb. 2, 2006); and Steward, supra, (Feb. 16, 2006).

A similar cloning strategy will be used to make pUCBHB1 cloning constructs for BoNT/B-TEV-NociceptinAP4B, a modified BoNT/B where amino acids 861-1291 of SEQ ID NO: 2 are replaced with SEQ ID NO: 101; BoNT/C1-TEV-NociceptinAP4B, a modified BoNT/C1 where amino acids 869-1291 of SEQ ID NO: 3 are replaced with SEQ ID NO: 101; BoNT/D-TEV-NociceptinAP4B, a modified BoNT/D where amino acids 865-1276 of SEQ ID NO: 4 are replaced with SEQ ID NO: 101; BoNT/E-TEV-NociceptinAP4B, a modified BoNT/E where amino acids 848-1252 of SEQ ID NO: 5 are replaced with SEQ ID NO: 101; BoNT/F-TEV-NociceptinAP4B, a modified BoNT/F where amino acids 867-1274 of SEQ ID NO: 6 are replaced with SEQ ID NO: 101; BoNT/G-TEV-NociceptinAP4B, a modified BoNT/G where amino acids 866-1297 of SEQ ID NO: 7 are replaced with SEQ ID NO: 101; TeNT-TEV-NociceptinAP4B, a modified TeNT where amino acids 882-1315 of SEQ ID NO: 8 are replaced with SEQ ID NO: 101; BaNT-TEV-NociceptinAP4B, a modified BaNT where amino acids 858-1268 of SEQ ID NO: 9 are replaced with SEQ ID NO: 101; and BuNT-TEV-NociceptinAP4B, a modified BuNT where amino acids 848-1251 of SEQ ID NO: 10 are replaced with SEQ ID NO: 101.

Likewise, a similar cloning strategy will be used to make pUCBHB1 cloning constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-TEV-AP4B that will replace the HC binding element from a Clostridial toxin the with an binding element comprising, e.g, an enkephalin peptide comprising SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54, SEQ ID NO: 55; a BAM22 peptide comprising amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60 or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61; an endomorphin peptide comprising SEQ ID NO: 62 or SEQ ID NO: 63; an enkephalin comprising SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69; a dynorphin comprising SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 72, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80, SEQ ID NO: 81, SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 85, SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, SEQ ID NO: 90, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, SEQ ID NO: 94, SEQ ID NO: 95, SEQ ID NO: 96, SEQ ID NO: 97, SEQ ID NO: 98, SEQ ID NO: 99 or SEQ ID NO: 100; a nociceptin comprising SEQ ID NO: 102, SEQ ID NO: 103, SEQ ID NO: 104, SEQ ID NO: 105, SEQ ID NO: 106, SEQ ID NO: 107, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110.

Likewise, a similar cloning strategy will be used to make pUCBHB1 cloning constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-AP4B comprising an exogenous protease cleavage site incorporated within the di-chain loop region, e.g, a bovine enterokinase protease cleavage site comprising SEQ ID NO: 21; a TEV protease site comprising SEQ ID NO: 24, SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 or SEQ ID NO: 33; a a human rhinovirus 3C protease cleavage site comprising SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39 or SEQ ID NO: 40; a subtilisin cleavage site comprising SEQ ID NO: 43, SEQ ID NO: 44 or SEQ ID NO: 45; a hydroxylamine cleavage site comprising SEQ ID NO: 46 or SEQ ID NO: 47; and a SUMO/ULP-1 protease cleavage site comprising SEQ ID NO: 48.

To construct pET29/BoNT/A-TEV-NociceptinAP4B, a pUCBHB1/BoNT/A-TEV-NociceptinAP4B construct will be digested with restriction endonucleases that 1) will excise the polynucleotide molecule encoding the open reading frame of BoNT/A-TEV-NociceptinAP4B; and 2) will enable this polynucleotide molecule to be operably-linked to a pET29 vector (EMD Biosciences-Novagen, Madison, Wis.). This insert will be subcloned using a T4 DNA ligase procedure into a pET29 vector that is digested with appropriate restriction endonucleases to yield pET29/BoNT/A-TEV-NociceptinAP4B. The ligation mixture will be transformed into chemically competent E. coli DH5a cells (Invitrogen, Inc, Carlsbad, Calif.) using a heat shock method, will be plated on 1.5% Luria-Bertani agar plates (pH 7.0) containing 50 pg/mL of Kanamycin, and will be placed in a 37° C. incubator for overnight growth. Bacteria containing expression constructs will be identified as Kanamycin resistant colonies. Candidate constructs will be isolated using an alkaline lysis plasmid mini-preparation procedure and will be analyzed by restriction endonuclease digest mapping to determine the presence and orientation of the insert. This cloning strategy will yield a pET29 expression construct comprising the polynucleotide molecule encoding the BoNT/A-TEV-NociceptinAP4B operably-linked to a carboxyl terminal polyhistidine affinity binding peptide.

A similar cloning strategy will be used to make pET29 expression constructs for other modified Clostridial toxin-TEV-NociceptinAP4B toxins, such as, e.g., BoNT/B-TEV-NociceptinAP4B, BoNT/C1-TEV-NociceptinAP4B, BoNT/D-TEV-NociceptinAP4B, BoNT/E-TEV-NociceptinAP4B, BoNT/F-TEV-NociceptinAP4B, BoNT/G-TEV-NociceptinAP4B, TeNT-TEV-NociceptinAP4B, BaNT-TEV-NociceptinAP4B, or BuNT-TEV-NociceptinAP4B. Likewise, a similar cloning strategy will be used to make pET29 expression constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-TEV-AP4B comprising a binding element such as, e.g, a binding element requiring a free amino-terminal amino acid like SEQ ID NO: 52 to SEQ ID NO: 100 or SEQ ID NO: 102 to SEQ ID NO: 110, as well as, amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60 or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61.

Furthermore, a similar cloning strategy will be used to make pET29 expression constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-AP4B comprising an exogenous protease cleavage site incorporated within the di-chain loop region such as, e.g, a bovine enterokinase protease cleavage site comprising SEQ ID NO: 21; a TEV protease site comprising SEQ ID NO: 24, SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 or SEQ ID NO: 33; a a human rhinovirus 3C protease cleavage site comprising SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39 or SEQ ID NO: 40; a subtilisin cleavage site comprising SEQ ID NO: 43, SEQ ID NO: 44 or SEQ ID NO: 45; a hydroxylamine cleavage site comprising SEQ ID NO: 46 or SEQ ID NO: 47; and a SUMO/ULP-1 protease cleavage site comprising SEQ ID NO: 48.

Example 18 Construction of an Activatable Clostridial Toxin Comprising a Centrally Presented Altered Targeting Domain

This example illustrates how to make an activatable Clostridial toxin disclosed in the present specification comprising a binding element located between two other domains of the modified toxin.

18a. A Therapeutic Element-Exogenous Protease Cleavage Site-Binding Element-Translocation Element Organization.

A polynucleotide molecule based on BoNT/A-ENT-NociceptinCP5A (SEQ ID NO: 127) will be synthesized and cloned into a pUCBHB1 vector as described in Example 17a. This polynucleotide molecule encodes a BoNT/A modified to replace amino acids 872-1296 of SEQ ID NO: 1, a BoNT/A HC binding element, with SEQ ID NO: 101, a nociceptin-RK peptide and to incorporate a bovine enterokinse protease site of SEQ ID NO: 21 within the di-chain loop region, arranged in an amino to carboxyl linear organization as depicted in FIG. 21A. Cleavage of an enterokinse cleavage site used to form the di-chain toxin also exposes the first amino acid of the nociceptin-RK binding element. If so desired, expression optimization to a different organism, such as, e.g., a bacteria, a yeast strain, an insect cell-line or a mammalian cell line, can be done as described above, see, e.g., Steward, supra, (Feb. 2, 2006); and Steward, supra, (Feb. 16, 2006).

A similar cloning strategy will be used to make pUCBHB1 cloning constructs for BoNT/B-ENT-NociceptinCP5A, a modified BoNT/B where amino acids 861-1291 of SEQ ID NO: 2 are replaced with SEQ ID NO: 101; BoNT/C1-ENT-NociceptinCP5A, a modified BoNT/C1 where amino acids 869-1291 of SEQ ID NO: 3 are replaced with SEQ ID NO: 101; BoNT/D-ENT-NociceptinCP5A, a modified BoNT/D where amino acids 865-1276 of SEQ ID NO: 4 are replaced with SEQ ID NO: 101; BoNT/E-ENT-NociceptinCP5A, a modified BoNT/E where amino acids 848-1252 of SEQ ID NO: 5 are replaced with SEQ ID NO: 101; BoNT/F-ENT-NociceptinCP5A, a modified BoNT/F where amino acids 867-1274 of SEQ ID NO: 6 are replaced with SEQ ID NO: 101; BoNT/G-ENT-NociceptinCP5A, a modified BoNT/G where amino acids 866-1297 of SEQ ID NO: 7 are replaced with SEQ ID NO: 101; TeNT-ENT-NociceptinCP5A, a modified TeNT where amino acids 882-1315 of SEQ ID NO: 8 are replaced with SEQ ID NO: 101; BaNT-ENT-NociceptinCP5A, a modified BaNT where amino acids 858-1268 of SEQ ID NO: 9 are replaced with SEQ ID NO: 101; and BuNT-ENT-NociceptinCP5A, a modified BuNT where amino acids 848-1251 of SEQ ID NO: 10 are replaced with SEQ ID NO: 101.

Likewise, a similar cloning strategy will be used to make pUCBHB1 cloning constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-ENT-CP5A that will replace the HC binding element from a Clostridial toxin the with an binding element comprising, e.g, an enkephalin peptide comprising SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54, SEQ ID NO: 55; a BAM22 peptide comprising amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60 or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61; an endomorphin peptide comprising SEQ ID NO: 62 or SEQ ID NO: 63; an enkephalin comprising SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69; a dynorphin comprising SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 72, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80, SEQ ID NO: 81, SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 85, SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, SEQ ID NO: 90, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, SEQ ID NO: 94, SEQ ID NO: 95, SEQ ID NO: 96, SEQ ID NO: 97, SEQ ID NO: 98, SEQ ID NO: 99 or SEQ ID NO: 100; a nociceptin comprising SEQ ID NO: 102, SEQ ID NO: 103, SEQ ID NO: 104, SEQ ID NO: 105, SEQ ID NO: 106, SEQ ID NO: 107, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110.

Likewise, a similar cloning strategy will be used to make pUCBHB1 cloning constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-CP5A comprising an exogenous protease cleavage site incorporated within the di-chain loop region, cleavage of which converts the single-chain polypeptide of the toxin into its di-chain form and also exposes the first amino acid of the binding element.

To construct pET29/BoNT/A-ENT-NociceptinCP5A, a pUCBHB1/BoNT/A-ENT-NociceptinCP5A construct will be digested with restriction endonucleases that 1) will excise the polynucleotide molecule encoding the open reading frame of BoNT/A-ENT-NociceptinCP5A; and 2) will enable this polynucleotide molecule to be operably-linked to a pET29 vector (EMD Biosciences-Novagen, Madison, Wis.). This insert will be subcloned using a T4 DNA ligase procedure into a pET29 vector that is digested with appropriate restriction endonucleases to yield pET29/BoNT/A-ENT-NociceptinCP5A. The ligation mixture will be transformed into chemically competent E. coli DH5a cells (Invitrogen, Inc, Carlsbad, Calif.) using a heat shock method, will be plated on 1.5% Luria-Bertan agar plates (pH 7.0) containing 50 pg/mL of Kanamycin, and will be placed in a 37° C. incubator for overnight growth. Bacteria containing expression constructs will be identified as Kanamycin resistant colonies. Candidate constructs will be isolated using an alkaline lysis plasmid mini-preparation procedure and will be analyzed by restriction endonuclease digest mapping to determine the presence and orientation of the insert. This cloning strategy will yield a pET29 expression construct comprising the polynucleotide molecule encoding the BoNT/A-TEV- NociceptinCP5A operably-linked to a carboxyl terminal polyhistidine affinity binding peptide.

A similar cloning strategy will be used to make pET29 expression constructs for other modified Clostridial toxin-ENT-NociceptinCP5A toxins, such as, e.g., BoNT/B-ENT-NociceptinCP5A, BoNT/C1-ENT-NociceptinCP5A, BoNT/D-ENT-NociceptinCP5A, BoNT/E-ENT-NociceptinCP5A, BoNT/F-ENT-NociceptinCP5A, BoNT/G-ENT-NociceptinCP5A, TeNT-ENT-NociceptinCP5A, BaNT-ENT-NociceptinCP5A, or BuNT-ENT-NociceptinCP5A. Likewise, a similar cloning strategy will be used to make pET29 expression constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-ENT-CP5B comprising a binding element such as, e.g, a binding element requiring a free amino-terminal amino acid like SEQ ID NO: 52 to SEQ ID NO: 100 or SEQ ID NO: 102 to SEQ ID NO: 110, as well as, amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60 or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61.

Furthermore, a similar cloning strategy will be used to make pET29 expression constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-CP5A comprising an exogenous protease cleavage site incorporated within the di-chain loop region such as, e.g, an exogenous protease cleavage site which upon cleavage converts the single-chain polypeptide of the toxin into its di-chain form and also exposes the first amino acid of the binding element.

18b. A Translocation Element-Exogenous Protease Cleavage Site-Binding Element-Therapeutic Element Organization.

A polynucleotide molecule based on BoNT/A-ENT-NociceptinCP5B (SEQ ID NO: 128) will be synthesized and cloned into a pUCBHB1 vector as described in Example 17a. This polynucleotide molecule encodes a BoNT/A modified to replace amino acids 872-1296 of SEQ ID NO: 1, a BoNT/A HC binding element, with SEQ ID NO: 101, a nociceptin-RK peptide and to incorporate a bovine enterokinse protease site of SEQ ID NO: 21 within the di-chain loop region, arranged in an amino to carboxyl linear organization as depicted in FIG. 21B. Cleavage of an enterokinse cleavage site used to form the di-chain toxin also exposes the first amino acid of the nociceptin-RK binding element. If so desired, expression optimization to a different organism, such as, e.g., a bacteria, a yeast strain, an insect cell-line or a mammalian cell line, can be done as described above, see, e.g., Steward, supra, (Feb. 2, 2006); and Steward, supra, (Feb. 16, 2006). A similar cloning strategy will be used to make pUCBHB1 cloning constructs for BoNT/B-ENT-NociceptinCP5B, a modified BoNT/B where amino acids 861-1291 of SEQ ID NO: 2 are replaced with SEQ ID NO: 101; BoNT/C1-ENT-NociceptinCP5B, a modified BoNT/C1 where amino acids 869-1291 of SEQ ID NO: 3 are replaced with SEQ ID NO: 101; BoNT/D-ENT-NociceptinCP5B, a modified BoNT/D where amino acids 865-1276 of SEQ ID NO: 4 are replaced with SEQ ID NO: 101; BoNT/E-ENT-NociceptinCP5B, a modified BoNT/E where amino acids 848-1252 of SEQ ID NO: 5 are replaced with SEQ ID NO: 101; BoNT/F-ENT-NociceptinCP5B, a modified BoNT/F where amino acids 867-1274 of SEQ ID NO: 6 are replaced with SEQ ID NO: 101; BoNT/G-ENT-NociceptinCP5B, a modified BoNT/G where amino acids 866-1297 of SEQ ID NO: 7 are replaced with SEQ ID NO: 101; TeNT-ENT-NociceptinCP5B, a modified TeNT where amino acids 882-1315 of SEQ ID NO: 8 are replaced with SEQ ID NO: 101; BaNT-ENT-NociceptinCP5B, a modified BaNT where amino acids 858-1268 of SEQ ID NO: 9 are replaced with SEQ ID NO: 101; and BuNT-ENT-NociceptinCP5B, a modified BuNT where amino acids 848-1251 of SEQ ID NO: 10 are replaced with SEQ ID NO: 101.

Likewise, a similar cloning strategy will be used to make pUCBHB1 cloning constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-ENT-CP5B that will replace the HC binding element from a Clostridial toxin the with an binding element comprising, e.g, an enkephalin peptide comprising SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54, SEQ ID NO: 55; a BAM22 peptide comprising amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60 or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61; an endomorphin peptide comprising SEQ ID NO: 62 or SEQ ID NO: 63; an enkephalin comprising SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69; a dynorphin comprising SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 72, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80, SEQ ID NO: 81, SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 85, SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, SEQ ID NO: 90, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, SEQ ID NO: 94, SEQ ID NO: 95, SEQ ID NO: 96, SEQ ID NO: 97, SEQ ID NO: 98, SEQ ID NO: 99 or SEQ ID NO: 100; a nociceptin comprising SEQ ID NO: 102, SEQ ID NO: 103, SEQ ID NO: 104, SEQ ID NO: 105, SEQ ID NO: 106, SEQ ID NO: 107, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110.

Likewise, a similar cloning strategy will be used to make pUCBHB1 cloning constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-CP5B comprising an exogenous protease cleavage site incorporated within the di-chain loop region, cleavage of which converts the single-chain polypeptide of the toxin into its di-chain form and also exposes the first amino acid of the binding element.

To construct pET29/BoNT/A-ENT-NociceptinCP5B, a pUCBHB1/BoNT/A-ENT-NociceptinCP5B construct will be digested with restriction endonucleases that 1) will excise the polynucleotide molecule encoding the open reading frame of BoNT/A-ENT-NociceptinCP5B; and 2) will enable this polynucleotide molecule to be operably-linked to a pET29 vector (EMD Biosciences-Novagen, Madison, Wis.). This insert will be subcloned using a T4 DNA ligase procedure into a pET29 vector that is digested with appropriate restriction endonucleases to yield pET29/BoNT/A-ENT-NociceptinCP5B. The ligation mixture will be transformed into chemically competent E. coli DH5a cells (Invitrogen, Inc, Carlsbad, Calif.) using a heat shock method, will be plated on 1.5% Luria-Bertani agar plates (pH 7.0) containing 50 pg/mL of Kanamycin, and will be placed in a 37° C. incubator for overnight growth. Bacteria containing expression constructs will be identified as Kanamycin resistant colonies. Candidate constructs will be isolated using an alkaline lysis plasmid mini-preparation procedure and will be analyzed by restriction endonuclease digest mapping to determine the presence and orientation of the insert. This cloning strategy will yield a pET29 expression construct comprising the polynucleotide molecule encoding the BoNT/A-ENT- NociceptinCP5B operably-linked to a carboxyl terminal polyhistidine affinity binding peptide.

A similar cloning strategy will be used to make pET29 expression constructs for other modified Clostridial toxin-ENT-NociceptinCP5B toxins, such as, e.g., BoNT/B-ENT-NociceptinCP5B, BoNT/C1-ENT-NociceptinCP5B, BoNT/D-ENT-NociceptinCP5B, BoNT/E-ENT-NociceptinCP5B, BoNT/F-ENT-NociceptinCP5B, BoNT/G-ENT-NociceptinCP5B, TeNT-ENT-NociceptinCP5B, BaNT-ENT-NociceptinCP5B, or BuNT-ENT-NociceptinCP5B. Likewise, a similar cloning strategy will be used to make pET29 expression constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-ENT-CP5B comprising a binding element such as, e.g, a binding element requiring a free amino-terminal amino acid like SEQ ID NO: 52 to SEQ ID NO: 100 or SEQ ID NO: 102 to SEQ ID NO: 110, as well as, amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60 or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61.

Furthermore, a similar cloning strategy will be used to make pET29 expression constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-CP5B comprising an exogenous protease cleavage site incorporated within the di-chain loop region such as, e.g, an exogenous protease cleavage site which upon cleavage converts the single-chain polypeptide of the toxin into its di-chain form and also exposes the first amino acid of the binding element.

Example 19 Construction of an Activatable Clostridial Toxin Comprising a Carboxyl-Terminally Presented Altered Targeting Domain

This example illustrates how to make an activatable Clostridial toxin disclosed in the present specification comprising a binding element located at the carboxyl terminus of the modified toxin.

19a. A Therapeutic Element-Exogenous Pro Tease Cleavage Site-Translocation Element-Binding Element Organization.

A polynucleotide molecule based on BoNT/A-TEV-GalaninXP6A (SEQ ID NO: 129) will be synthesized and cloned into a pUCBHB1 vector as described in Example 17a. This polynucleotide molecule encodes a BoNT/A modified to replace amino acids 872-1296 of SEQ ID NO: 1, a BoNT/A HC binding element, with SEQ ID NO: 101, a nociceptin-RK peptide and to incorporate a TEV protease site of SEQ ID NO: 24 within the di-chain loop region, arranged in an amino to carboxyl linear organization as depicted in FIG. 22A. If so desired, expression optimization to a different organism, such as, e.g., a bacteria, a yeast strain, an insect cell-line or a mammalian cell line, can be done as described above, see, e.g., Steward, supra, (Feb. 2, 2006); and Steward, supra, (Feb. 16, 2006).

A similar cloning strategy will be used to make pUCBHB1 cloning constructs for BoNT/B-TEV-GalaninXP6A, a modified BoNT/B where amino acids 861-1291 of SEQ ID NO: 2 are replaced with SEQ ID NO: 101; BoNT/C1-TEV-GalaninXP6A, a modified BoNT/C1 where amino acids 869-1291 of SEQ ID NO: 3 are replaced with SEQ ID NO: 101; BoNT/D-TEV-GalaninXP6A, a modified BoNT/D where amino acids 865-1276 of SEQ ID NO: 4 are replaced with SEQ ID NO: 101; BoNT/E-TEV-GalaninXP6A, a modified BoNT/E where amino acids 848-1252 of SEQ ID NO: 5 are replaced with SEQ ID NO: 101; BoNT/F-TEV-GalaninXP6A, a modified BoNT/F where amino acids 867-1274 of SEQ ID NO: 6 are replaced with SEQ ID NO: 101; BoNT/G-TEV-GalaninXP6A, a modified BoNT/G where amino acids 866-1297 of SEQ ID NO: 7 are replaced with SEQ ID NO: 101; TeNT-TEV-GalaninXP6A, a modified TeNT where amino acids 882-1315 of SEQ ID NO: 8 are replaced with SEQ ID NO: 101; BaNT-TEV-GalaninXP6A, a modified BaNT where amino acids 858-1268 of SEQ ID NO: 9 are replaced with SEQ ID NO: 101; and BuNT-TEV-GalaninXP6A, a modified BuNT where amino acids 848-1251 of SEQ ID NO: 10 are replaced with SEQ ID NO: 101.

Likewise, a similar cloning strategy will be used to make pUCBHB1 cloning constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-TEV-XP6A that will replace the HC binding element from a Clostridial toxin the with an binding element comprising, e.g, an enkephalin peptide comprising SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54, SEQ ID NO: 55; a BAM22 peptide comprising amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60 or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61; an endomorphin peptide comprising SEQ ID NO: 62 or SEQ ID NO: 63; an enkephalin comprising SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69; a dynorphin comprising SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 72, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80, SEQ ID NO: 81, SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 85, SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, SEQ ID NO: 90, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, SEQ ID NO: 94, SEQ ID NO: 95, SEQ ID NO: 96, SEQ ID NO: 97, SEQ ID NO: 98, SEQ ID NO: 99 or SEQ ID NO: 100; a nociceptin comprising SEQ ID NO: 102, SEQ ID NO: 103, SEQ ID NO: 104, SEQ ID NO: 105, SEQ ID NO: 106, SEQ ID NO: 107, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110.

Likewise, a similar cloning strategy will be used to make pUCBHB1 cloning constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-XP6A comprising an exogenous protease cleavage site incorporated within the di-chain loop region, e.g, a bovine enterokinase protease cleavage site comprising SEQ ID NO: 21; a TEV protease site comprising SEQ ID NO: 24, SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 or SEQ ID NO: 33; a a human rhinovirus 3C protease cleavage site comprising SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39 or SEQ ID NO: 40; a subtilisin cleavage site comprising SEQ ID NO: 43, SEQ ID NO: 44 or SEQ ID NO: 45; a hydroxylamine cleavage site comprising SEQ ID NO: 46 or SEQ ID NO: 47; and a SUMO/ULP-1 protease cleavage site comprising SEQ ID NO: 48. To construct pET29/BoNT/A-TEV-GalaninXP6A, a pUCBHB1/BoNT/A-TEV-GalaninXP6A construct will be digested with restriction endonucleases that 1) will excise the polynucleotide molecule encoding the open reading frame of BoNT/A-TEV-GalaninXP6A; and 2) will enable this polynucleotide molecule to be operably-linked to a pET29 vector (EMD Biosciences-Novagen, Madison, Wis.). This insert will be subcloned using a T4 DNA ligase procedure into a pET29 vector that is digested with appropriate restriction endonucleases to yield pET29/BoNT/A-TEV-GalaninXP6A. The ligation mixture will be transformed into chemically competent E. coli DH5a cells (Invitrogen, Inc, Carlsbad, Calif.) using a heat shock method, will be plated on 1.5% Luria-Bertani agar plates (pH 7.0) containing 50 pg/mL of Kanamycin, and will be placed in a 37° C. incubator for overnight growth. Bacteria containing expression constructs will be identified as Kanamycin resistant colonies. Candidate constructs will be isolated using an alkaline lysis plasmid mini-preparation procedure and will be analyzed by restriction endonuclease digest mapping to determine the presence and orientation of the insert. This cloning strategy will yield a pET29 expression construct comprising the polynucleotide molecule encoding the BoNT/A-TEV- GalaninXP6A operably-linked to a carboxyl terminal polyhistidine affinity binding peptide.

A similar cloning strategy will be used to make pET29 expression constructs for other modified Clostridial toxin-TEV-GalaninXP6A toxins, such as, e.g., BoNT/B-TEV-GalaninXP6A, BoNT/C1-TEV-GalaninXP6A, BoNT/D-TEV-GalaninXP6A, BoNT/E-TEV-GalaninXP6A, BoNT/F-TEV-GalaninXP6A, BoNT/G-TEV-GalaninXP6A, TeNT-TEV-GalaninXP6A, BaNT-TEV-GalaninXP6A, or BuNT-TEV-GalaninXP6A. Likewise, a similar cloning strategy will be used to make pET29 expression constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-TEV-XP6A comprising a binding element such as, e.g, a binding element requiring a free amino-terminal amino acid like SEQ ID NO: 52 to SEQ ID NO: 100 or SEQ ID NO: 102 to SEQ ID NO: 110, as well as, amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60 or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61.

Furthermore, a similar cloning strategy will be used to make pET29 expression constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-XP6A comprising an exogenous protease cleavage site incorporated within the di-chain loop region such as, e.g, a bovine enterokinase protease cleavage site comprising SEQ ID NO: 21; a TEV protease site comprising SEQ ID NO: 24, SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 or SEQ ID NO: 33; a a human rhinovirus 3C protease cleavage site comprising SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39 or SEQ ID NO: 40; a subtilisin cleavage site comprising SEQ ID NO: 43, SEQ ID NO: 44 or SEQ ID NO: 45; a hydroxylamine cleavage site comprising SEQ ID NO: 46 or SEQ ID NO: 47; and a SUMO/ULP-1 protease cleavage site comprising SEQ ID NO: 48.

19b. A Translocation Element-Exogenous Protease Cleavage Site-Therapeutic Element-Binding Element Organization.

A polynucleotide molecule based on BoNT/A-TEV-GalaninXP6B (SEQ ID NO: 130) will be synthesized and cloned into a pUCBHB1 vector as described in Example 17a. This polynucleotide molecule encodes a BoNT/A modified to replace amino acids 872-1296 of SEQ ID NO: 1, a BoNT/A HC binding element, with SEQ ID NO: 101, a nociceptin-RK peptide and to incorporate a TEV protease site of SEQ ID NO: 24 within the di-chain loop region, arranged in an amino to carboxyl linear organization as depicted in FIG. 22B. If so desired, expression optimization to a different organism, such as, e.g., a bacteria, a yeast strain, an insect cell-line or a mammalian cell line, can be done as described above, see, e.g., Steward, supra, (Feb. 2, 2006); and Steward, supra, (Feb. 16, 2006).

A similar cloning strategy will be used to make pUCBHB1 cloning constructs for BoNT/B-TEV-GalaninXP6B, a modified BoNT/B where amino acids 861-1291 of SEQ ID NO: 2 are replaced with SEQ ID NO: 101; BoNT/C1-TEV-GalaninXP6B, a modified BoNT/C1 where amino acids 869-1291 of SEQ ID NO: 3 are replaced with SEQ ID NO: 101; BoNT/D-TEV-GalaninXP6B, a modified BoNT/D where amino acids 865-1276 of SEQ ID NO: 4 are replaced with SEQ ID NO: 101; BoNT/E-TEV-GalaninXP6B, a modified BoNT/E where amino acids 848-1252 of SEQ ID NO: 5 are replaced with SEQ ID NO: 101; BoNT/F-TEV-GalaninXP6B, a modified BoNT/F where amino acids 867-1274 of SEQ ID NO: 6 are replaced with SEQ ID NO: 101; BoNT/G-TEV-GalaninXP6B, a modified BoNT/G where amino acids 866-1297 of SEQ ID NO: 7 are replaced with SEQ ID NO: 101; TeNT-TEV-GalaninXP6B, a modified TeNT where amino acids 882-1315 of SEQ ID NO: 8 are replaced with SEQ ID NO: 101; BaNT-TEV-GalaninXP6B, a modified BaNT where amino acids 858-1268 of SEQ ID NO: 9 are replaced with SEQ ID NO: 101; and BuNT-TEV-GalaninXP6B, a modified BuNT where amino acids 848-1251 of SEQ ID NO: 10 are replaced with SEQ ID NO: 101.

Likewise, a similar cloning strategy will be used to make pUCBHB1 cloning constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-TEV-XP6B that will replace the HC binding element from a Clostridial toxin the with an binding element comprising, e.g, an enkephalin peptide comprising SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54, SEQ ID NO: 55; a BAM22 peptide comprising amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60 or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61; an endomorphin peptide comprising SEQ ID NO: 62 or SEQ ID NO: 63; an enkephalin comprising SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO: 69; a dynorphin comprising SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 72, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80, SEQ ID NO: 81, SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 85, SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, SEQ ID NO: 90, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, SEQ ID NO: 94, SEQ ID NO: 95, SEQ ID NO: 96, SEQ ID NO: 97, SEQ ID NO: 98, SEQ ID NO: 99 or SEQ ID NO: 100; a nociceptin comprising SEQ ID NO: 102, SEQ ID NO: 103, SEQ ID NO: 104, SEQ ID NO: 105, SEQ ID NO: 106, SEQ ID NO: 107, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO: 110.

Likewise, a similar cloning strategy will be used to make pUCBHB1 cloning constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-XP6B comprising an exogenous protease cleavage site incorporated within the di-chain loop region, e.g, a bovine enterokinase protease cleavage site comprising SEQ ID NO: 21; a TEV protease site comprising SEQ ID NO: 24, SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 or SEQ ID NO: 33; a a human rhinovirus 3C protease cleavage site comprising SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39 or SEQ ID NO: 40; a subtilisin cleavage site comprising SEQ ID NO: 43, SEQ ID NO: 44 or SEQ ID NO: 45; a hydroxylamine cleavage site comprising SEQ ID NO: 46 or SEQ ID NO: 47; and a SUMO/ULP-1 protease cleavage site comprising SEQ ID NO: 48.

To construct pET29/BoNT/A-TEV-NociceptinAP4B, a pUCBHB1/BoNT/A-TEV-GalaninXP6B construct will be digested with restriction endonucleases that 1) will excise the polynucleotide molecule encoding the open reading frame of BoNT/A-TEV-GalaninXP6B; and 2) will enable this polynucleotide molecule to be operably-linked to a pET29 vector (EMD Biosciences-Novagen, Madison, Wis.). This insert will be subcloned using a T4 DNA ligase procedure into a pET29 vector that is digested with appropriate restriction endonucleases to yield pET29/BoNT/A-TEV-GalaninXP6B. The ligation mixture will be transformed into chemically competent E. coli DH5a cells (Invitrogen, Inc, Carlsbad, Calif.) using a heat shock method, will be plated on 1.5% Luria-Bertani agar plates (pH 7.0) containing 50 pg/mL of Kanamycin, and will be placed in a 37° C. incubator for overnight growth. Bacteria containing expression constructs will be identified as Kanamycin resistant colonies. Candidate constructs will be isolated using an alkaline lysis plasmid mini-preparation procedure and will be analyzed by restriction endonuclease digest mapping to determine the presence and orientation of the insert. This cloning strategy will yield a pET29 expression construct comprising the polynucleotide molecule encoding the BoNT/A-TEV- GalaninXP6B operably-linked to a carboxyl terminal polyhistidine affinity binding peptide.

A similar cloning strategy will be used to make pET29 expression constructs for other modified Clostridial toxin-TEV-GalaninXP6B toxins, such as, e.g., BoNT/B-TEV-GalaninXP6B, BoNT/C1-TEV-GalaninXP6B, BoNT/D-TEV-GalaninXP6B, BoNT/E-TEV-GalaninXP6B, BoNT/F-TEV-GalaninXP6B, BoNT/G-TEV-GalaninXP6B, TeNT-TEV-GalaninXP6B, BaNT-TEV-GalaninXP6B, or BuNT-TEV-GalaninXP6B. Likewise, a similar cloning strategy will be used to make pET29 expression constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-TEV-XP6B comprising a binding element such as, e.g, a binding element requiring a free amino-terminal amino acid like SEQ ID NO: 52 to SEQ ID NO: 100 or SEQ ID NO: 102 to SEQ ID NO: 110, as well as, amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 56; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 57; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 58; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 59; amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 60 or amino acids 1-12, amino acids 6-22, amino acids 8-22 or amino acids 1-22 of SEQ ID NO: 61.

Furthermore, a similar cloning strategy will be used to make pET29 expression constructs comprising a polynucleotide molecule encoding a modified Clostridial toxin-XP6B comprising an exogenous protease cleavage site incorporated within the di-chain loop region such as, e.g, a bovine enterokinase protease cleavage site comprising SEQ ID NO: 21; a TEV protease site comprising SEQ ID NO: 24, SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 or SEQ ID NO: 33; a a human rhinovirus 3C protease cleavage site comprising SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39 or SEQ ID NO: 40; a subtilisin cleavage site comprising SEQ ID NO: 43, SEQ ID NO: 44 or SEQ ID NO: 45; a hydroxylamine cleavage site comprising SEQ ID NO: 46 or SEQ ID NO: 47; and a SUMO/ULP-1 protease cleavage site comprising SEQ ID NO: 48.

Example 20 Expression of Activatable Clostridial Toxins in a Bacterial Cell

The following example illustrates a procedure useful for expressing any of the activatable Clostridial toxins disclosed in the present specification in a bacterial cell.

An expression construct, such as, e.g., any of the expression constructs in Examples 17-19, will be introduced into chemically competent E. coli BL21 (DE3) cells (Invitrogen, Inc, Carlsbad, Calif.) using a heat-shock transformation protocol. The heat-shock reaction will be plated onto 1.5% Luria-Bertani agar plates (pH 7.0) containing 50 μg/mL of Kanamycin and will be placed in a 37° C. incubator for overnight growth. Kanamycin-resistant colonies of transformed E. coli containing the expression construct will be used to inoculate a baffled flask containing 3.0 mL of PA-0.5G media containing 50 μg/mL of Kanamycin which will then placed in a 37° C. incubator, shaking at 250 rpm, for overnight growth. The resulting overnight starter culture will be used to inoculate a 3 L baffled flask containing ZYP-5052 autoinducing media containing 50 μg/mL of Kanamycin at a dilution of 1:1000. Culture volumes will range from about 600 mL (20% flask volume) to about 750 mL (25% flask volume). These cultures will be grown in a 37° C. incubator shaking at 250 rpm for approximately 5.5 hours and will be then transferred to a 16° C. incubator shaking at 250 rpm for overnight expression. Cells will be harvested by centrifugation (4,000 rpm at 4° C. for 20-30 minutes) and will be used immediately, or will be stored dry at −80° C. until needed.

Example 21 Purification and Quantification of Activatable Clostridial Toxins

The following example illustrates methods useful for purification and quantification of any activatable Clostridial toxins disclosed in the present specification.

For immobilized metal affinity chromatography (IMAC) protein purification, E. coli BL21 (DE3) cell pellets used to express a modified Clostridial toxin, as described in Example 20, will be resuspended in Column Binding Buffer (25 mM N-(2-hydroxyethyl) piperazine-N′-(2-ethanesulfonic acid) (HEPES), pH 7.8; 500 mM sodium chloride; 10 mM imidazole; 2× Protease Inhibitor Cocktail Set III (EMD Biosciences-Calbiochem, San Diego Calif.); 5 units/mL of Benzonase (EMD Biosciences—Novagen, Madison, Wis.); 0.1% (v/v) TRITON-X® 100, 4-octylphenol polyethoxylate; 10% (v/v) glycerol), and will then be transferred to a cold Oakridge centrifuge tube. The cell suspension will be sonicated on ice (10-12 pulses of 10 seconds at 40% amplitude with 60 seconds cooling intervals on a Branson Digital Sonifier) in order to lyse the cells and then is centrifuged (16,000 rpm at 4□C. for 20 minutes) to clarify the lysate. An immobilized metal affinity chromatography column will be prepared using a 20 mL Econo-Pac column support (Bio-Rad Laboratories, Hercules, Calif.) packed with 2.5-5.0 mL of TALON™ SuperFlow Co2+ affinity resin (BD Biosciences-Clontech, Palo Alto, Calif.), which will then be equilibrated by rinsing with 5 column volumes of deionized, distilled water, followed by 5 column volumes of Column Binding Buffer. The clarified lysate will be applied slowly to the equilibrated column by gravity flow (approximately 0.25-0.3 mL/minute). The column will then be washed with 5 column volumes of Column Wash Buffer (N-(2-hydroxyethyl) piperazine-N′-(2-ethanesulfonic acid) (HEPES), pH 7.8; 500 mM sodium chloride; 10 mM imidazole; 0.1% (v/v) Triton-X® 100, 4-octylphenol polyethoxylate; 10% (v/v) glycerol). The modified Clostridial toxin will be eluted with 20-30 mL of Column Elution Buffer (25 mM N-(2-hydroxyethyl) piperazine-N′-(2-ethanesulfonic acid) (HEPES), pH 7.8; 500 mM sodium chloride; 500 mM imidazole; 0.1% (v/v) TRITON-X® 100, 4-octylphenol polyethoxylate; 10% (v/v) glycerol) and will be collected in approximately twelve 1 mL fractions. The amount of modified Clostridial toxin contained in each elution fraction will be determined by a Bradford dye assay. In this procedure, 20 μL aliquots of each 1.0 mL fraction will be combined with 200 μL of Bio-Rad Protein Reagent (Bio-Rad Laboratories, Hercules, Calif.), diluted 1 to 4 with deionized, distilled water, and then the intensity of the colorimetric signal will be measured using a spectrophotometer. The five fractions with the strongest signal will be considered the elution peak and will be combined together. Total protein yield will be determined by estimating the total protein concentration of the pooled peak elution fractions using bovine gamma globulin as a standard (Bio-Rad Laboratories, Hercules, Calif.).

For purification of a modified Clostridial toxin using a FPLC desalting column, a HiPrep™ 26/10 size exclusion column (Amersham Biosciences, Piscataway, N.J.) will be pre-equilibrated with 80 mL of 4° C. Column Buffer (50 mM sodium phosphate, pH 6.5). After the column is equilibrated, a modified Clostridial toxin sample will be applied to the size exclusion column with an isocratic mobile phase of 4° C. Column Buffer and at a flow rate of 10 mL/minute using a BioLogic DuoFlow chromatography system (Bio-Rad Laboratories, Hercules, Calif.). The desalted modified Clostridial toxin sample will be collected as a single fraction of approximately 7-12 mL.

For purification of a modified Clostridial toxin using a FPLC ion exchange column, a modified Clostridial toxin sample that has been desalted following elution from an IMAC column will be applied to a 1 mL Q1™ anion exchange column (Bio-Rad Laboratories, Hercules, Calif.) using a BioLogic DuoFlow chromatography system (Bio-Rad Laboratories, Hercules, Calif.). The sample will be applied to the column in 4° C. Column Buffer (50 mM sodium phosphate, pH 6.5) and will be eluted by linear gradient with 4° C. Elution Buffer (50 mM sodium phosphate, 1 M sodium chloride, pH 6.5) as follows: step 1, 5.0 mL of 5% Elution Buffer at a flow rate of 1 mL/minute; step 2, 20.0 mL of 5-30% Elution Buffer at a flow rate of 1 mL/minute; step 3, 2.0 mL of 50% Elution Buffer at a flow rate of 1.0 mL/minute; step 4, 4.0 mL of 100% Elution Buffer at a flow rate of 1.0 mL/minute; and step 5, 5.0 mL of 0% Elution Buffer at a flow rate of 1.0 mL/minute. Elution of modified Clostridial toxin from the column will be monitored at 280, 260, and 214 nm, and peaks absorbing above a minimum threshold (0.01 au) at 280 nm will be collected. Most of the modified Clostridial toxin will be eluted at a sodium chloride concentration of approximately 100 to 200 mM. Average total yields of modified Clostridial toxin will be determined by a Bradford assay.

Expression of a modified Clostridial toxin will be analyzed by polyacrylamide gel electrophoresis. Samples purified using the procedure described above are added to 2×LDS Sample Buffer (Invitrogen, Inc, Carlsbad, Calif.) and will be separated by MOPS polyacrylamide gel electrophoresis using NuPAGE® Novex 4-12% Bis-Tris precast polyacrylamide gels (Invitrogen, Inc, Carlsbad, Calif.) under denaturing, reducing conditions. Gels will be stained with SYPRO® Ruby (Bio-Rad Laboratories, Hercules, Calif.) and the separated polypeptides will be imaged using a Fluor-S MAX MultiImager (Bio-Rad Laboratories, Hercules, Calif.) for quantification of modified Clostridial toxin expression levels. The size and amount of modified Clostridial toxin will be determined by comparison to MagicMark™ protein molecular weight standards (Invitrogen, Inc, Carlsbad, Calif.).

Expression of modified Clostridial toxin will also be analyzed by Western blot analysis. Protein samples purified using the procedure described above will be added to 2×LDS Sample Buffer (Invitrogen, Inc, Carlsbad, Calif.) and will be separated by MOPS polyacrylamide gel electrophoresis using NuPAGE® Novex 4-12% Bis-Tris precast polyacrylamide gels (Invitrogen, Inc, Carlsbad, Calif.) under denaturing, reducing conditions. Separated polypeptides will be transferred from the gel onto polyvinylidene fluoride (PVDF) membranes (Invitrogen, Inc, Carlsbad, Calif.) by Western blotting using a Trans-Blot® SD semi-dry electrophoretic transfer cell apparatus (Bio-Rad Laboratories, Hercules, Calif.). PVDF membranes will be blocked by incubating at room temperature for 2 hours in a solution containing 25 mM Tris-Buffered Saline (25 mM 2-amino-2-hydroxymethyl-1,3-propanediol hydrochloric acid (Tris-HCl) (pH 7.4), 137 mM sodium chloride, 2.7 mM potassium chloride), 0.1% TWEEN-20®, polyoxyethylene (20) sorbitan monolaureate, 2% bovine serum albumin, 5% nonfat dry milk. Blocked membranes will be incubated at 4° C. for overnight in Tris-Buffered Saline TWEEN-20® (25 mM Tris-Buffered Saline, 0.1% TWEEN-20®, polyoxyethylene (20) sorbitan monolaureate) containing appropriate primary antibodies as a probe. Primary antibody probed blots will be washed three times for 15 minutes each time in Tris-Buffered Saline TWEEN-20®. Washed membranes will be incubated at room temperature for 2 hours in Tris-Buffered Saline TWEEN-20® containing an appropriate immunoglobulin G antibody conjugated to horseradish peroxidase as a secondary antibody. Secondary antibody-probed blots will be washed three times for 15 minutes each time in Tris-Buffered Saline TWEEN-20®. Signal detection of the labeled modified Clostridial toxin will be visualized using the ECL Plus™ Western Blot Detection System (Amersham Biosciences, Piscataway, N.J.) and will be imaged with a Typhoon 9410 Variable Mode Imager (Amersham Biosciences, Piscataway, N.J.) for quantification of modified Clostridial toxin expression levels.

Although aspects of the present invention have been described with reference to the disclosed embodiments, one skilled in the art will readily appreciate that the specific examples disclosed are only illustrative of these aspects and in no way limit the present invention. Various modifications can be made without departing from the spirit of the present invention.

Those of skill in the art will understand that the Examples provided herein describe preferred compositions and methods, and that a variety of different cloning strategies, protease cleavage sites, and specific binding complex members may be employed in the practice and use of the present invention while remaining within the invention's scope. Additionally, different di-chain or binary toxin molecules and modified versions thereof (for example, BoNT/B-E and modified variants thereof) may be used as the basis for the methods and compositions of the present invention. 

1. A single-chain polypeptide comprising: a) a first amino acid sequence region comprising i) a first domain comprising a binding element comprising an opioid peptide able to preferentially interact with an opioid peptide receptor under physiological conditions; and ii) a second domain comprising a translocation element comprising a Clostridial neurotoxin heavy chain able to facilitate the transfer of said single-chain polypeptide across a vesicular membrane; and b) a second amino acid sequence region comprising a therapeutic element comprising a Clostridial neurotoxin light chain having biological activity when released into the cytoplasm of said target cell; c) a third amino acid sequence region comprising an exogenous protease cleavage site; wherein said first and second amino acid sequence regions are separated by said third amino acid sequence region.
 2. The polypeptide of claim 1, wherein said opioid peptide comprises an enkephalin peptide, a BAM22 peptide, an endomorphin peptide, an endorphin peptide, a dynorphin peptide, a nociceptin peptide or a hemorphin peptide.
 3. The polypeptide of claim 2, wherein said enkephalin peptide comprises a Leu-enkephalin, a Met-enkephalin, a Met-enkephalin MRGL or a Met-enkephalin MRF
 4. The polypeptide of claim 2, wherein said enkephalin comprises SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54 and SEQ ID NO:
 55. 5. The polypeptide of claim 2, wherein said BAM22 peptide comprises a BAM22 peptide (1-12), a BAM22 peptide (6-22), a BAM22 peptide (8-22) or a BAM22 peptide (1-22).
 6. The polypeptide of claim 2, wherein said BAM22 peptide comprises amino acids 1-12 of SEQ ID NO: 56, amino acids 6-22 of SEQ ID NO: 56, amino acids 8-22 of SEQ ID NO: 56, amino acids 1-22 of SEQ ID NO: 56, amino acids 1-12 of SEQ ID NO: 57, amino acids 6-22 of SEQ ID NO: 57, amino acids 8-22 of SEQ ID NO: 57, amino acids 1-22 of SEQ ID NO: 57, amino acids 1-12 of SEQ ID NO: 58, amino acids 6-22 of SEQ ID NO: 58, amino acids 8-22 of SEQ ID NO: 58, amino acids 1-22 of SEQ ID NO: 58, amino acids 1-12 of SEQ ID NO: 59, amino acids 6-22 of SEQ ID NO: 59, amino acids 8-22 of SEQ ID NO: 59, amino acids 1-22 of SEQ ID NO: 59, amino acids 1-12 of SEQ ID NO: 60, amino acids 6-22 of SEQ ID NO: 60, amino acids 8-22 of SEQ ID NO: 60, amino acids 1-22 of SEQ ID NO: 60, amino acids 1-12 of SEQ ID NO: 61, amino acids 6-22 of SEQ ID NO: 61, amino acids 8-22 of SEQ ID NO: 61 and amino acids 1-22 of SEQ ID NO:
 61. 7. The polypeptide of claim 2, wherein said endomorphin peptide comprises an endomorphin-1 peptide or an endomorphin-2 peptide.
 8. The polypeptide of claim 2, wherein said endomorphin peptide comprises SEQ ID NO: 62 or SEQ ID NO:
 63. 9. The polypeptide of claim 2, wherein said endorphin peptide comprises an endorphin-α peptide, a neoendorphin-a peptide, an endorphin-β peptide, a neoendorphin-β peptide or an endorphin-γ peptide.
 10. The polypeptide of claim 2, wherein said endorphin comprises SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68 or SEQ ID NO:
 69. 11. The polypeptide of claim 2, wherein said dynorphin peptide comprises a dynorphin A peptide, a dynorphin B peptide or a rimorphin peptide.
 12. The polypeptide of claim 2, wherein said dynorphin peptide comprises SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 72, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80, SEQ ID NO: 81, SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 85, SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, SEQ ID NO: 90, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, SEQ ID NO: 94, SEQ ID NO: 95, SEQ ID NO: 96, SEQ ID NO: 97, SEQ ID NO: 98, SEQ ID NO: 99 or SEQ ID NO:
 100. 13. The polypeptide of claim 2, wherein said nociceptin peptide comprises a nociceptin RK, a nociceptin, a neuropeptide 1, a neuropeptide 2 or a neuropeptide
 3. 14. The polypeptide of claim 2, wherein said nociceptin peptide comprises SEQ ID NO: 101, SEQ ID NO: 102, SEQ ID NO: 103, SEQ ID NO: 104, SEQ ID NO: 105, SEQ ID NO: 106, SEQ ID NO: 107, SEQ ID NO: 108, SEQ ID NO: 109 or SEQ ID NO:
 110. 15. The polypeptide of claim 1, wherein said translocation element comprises a Clostridium botulinum neurotoxin heavy chain.
 16. The polypeptide of claim 15, wherein said Clostridium botulinum neurotoxin heavy chain translocation element is selected from the group consisting of a Clostridium botulinum serotype A neurotoxin heavy chain, a Clostridium botulinum serotype B neurotoxin heavy chain, a Clostridium botulinum serotype C1 neurotoxin heavy chain, a Clostridium botulinum serotype D neurotoxin heavy chain, a Clostridium botulinum serotype E neurotoxin heavy chain, a Clostridium botulinum serotype F neurotoxin heavy chain and a Clostridium botulinum serotype G neurotoxin heavy chain.
 17. The polypeptide of claim 1, wherein said translocation element comprises a Clostridium tetani neurotoxin heavy chain.
 18. The polypeptide of claim 17, wherein said therapeutic element comprises a Clostridium botulinum neurotoxin light chain.
 19. The polypeptide of claim 18, wherein said Clostridium botulinum neurotoxin light chain therapeutic element is selected from the group consisting of a Clostridium botulinum serotype A neurotoxin light chain, a Clostridium botulinum serotype B neurotoxin light chain, a Clostridium botulinum serotype C1 neurotoxin light chain, a Clostridium botulinum serotype D neurotoxin light chain, a Clostridium botulinum serotype E neurotoxin light chain, a Clostridium botulinum serotype F neurotoxin light chain and a Clostridium botulinum serotype G neurotoxin light chain.
 20. The polypeptide of claim 1, wherein said therapeutic element comprises a Clostridium tetani neurotoxin light chain.
 21. The polypeptide of claim 1, wherein said exogenous protease cleavage site comprises a bovine enterokinase, a tobacco etch virus protease, a protease derived from Bacillus subtilus, a protease derived from Bacillus amyliquifaciens, a protease derived from a rhinovirus, a papain, an insect papain homolog, or a crustacian papain homolog.
 22. The polypeptide of claim 1, wherein said exogenous protease cleavage site comprises a non-human enterokinase cleavage site, a tobacco etch virus protease cleavage site, a tobacco vein mottling virus protease cleavage site, a human rhinovirus 3C protease cleavage site, a subtilisin cleavage site, a hydroxylamine cleavage site, a SUMO/ULP-1 protease cleavage site, or a non-human Caspase 3 protease cleavage site.
 23. The polypeptide of claim 22, wherein said non-human enterokinase cleavage site comprises SEQ ID NO:
 21. 24. The polypeptide of claim 22, wherein said tobacco etch virus protease cleavage site comprises SEQ ID NO: 22 or SEQ ID NO:
 23. 25. The polypeptide of claim 22, wherein said tobacco etch virus protease cleavage site comprises SEQ ID NO: 24, SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32 or SEQ ID NO:
 33. 26. The polypeptide of claim 22, wherein said tobacco vein mottling virus protease cleavage site comprises SEQ ID NO: 132 or SEQ ID NO:
 133. 27. The polypeptide of claim 22, wherein said tobacco vein mottling virus protease cleavage site comprises SEQ ID NO: 134, SEQ ID NO: 135, SEQ ID NO: 136, or SEQ ID NO:
 137. 28. The polypeptide of claim 22, wherein said human rhinovirus 3C protease cleavage site comprises SEQ ID NO:34.
 29. The polypeptide of claim 22, wherein said human rhinovirus 3C protease cleavage site comprises SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39 or SEQ ID NO:
 40. 28. The polypeptide of claim 22, wherein said subtilisin cleavage site comprises SEQ ID NO:41 or SEQ ID NO:42.
 29. The polypeptide of claim 22, wherein said subtilisin cleavage site comprises SEQ ID NO: 43, SEQ ID NO: 44, or SEQ ID NO:
 45. 30. The polypeptide of claim 22, wherein said hydroxylamine cleavage site comprises SEQ ID NO:46 or SEQ ID NO:47.
 31. The polypeptide of claim 22, wherein said non-human Caspase 3 protease cleavage site comprises SEQ ID NO:
 139. 32. The polypeptide of claim 22, wherein said non-human Caspase 3 protease cleavage site comprises SEQ ID NO: 139, SEQ ID NO: 140, SEQ ID NO: 141, SEQ ID NO: 142, SEQ ID NO: 143 or SEQ ID NO:
 144. 33. The polypeptide of claim 1, wherein said polypeptide comprises a fourth amino acid sequence region comprising a target-binding portion of a binding tag.
 34. A nucleotide sequence encoding a single-chain polypeptide according to claim
 1. 35. The nucleotide sequence of claim 34, further comprising an expression vector.
 36. A method of making a single-chain polypeptide comprising: a) inserting a nucleotide sequence of claims 35 into a suitable host cell; b) growing said host cell in culture; and c) permitting or inducing the host cell to express the single chain polypeptide encoded by said nucleotide sequence.
 37. A method of purifying a single chain-polypeptide comprising: a) lysing a host cell containing a nucleotide sequence expressing a single-chain polypeptide to produce a cell lysate, said single-chain polypeptide according to claim 1; b) contacting said cell lysate with a target compound so as to form a specific binding complex capable of being immobilized comprising said binding tag and said target compound; and c) separating said binding complex from said cell lysate.
 38. A method of activating a single-chain polypeptide, the method comprising the step of incubating an single-chain polypeptide according to claim 1 with an exogenous protease; wherein the exogenous protease cleaves the exogenous protease cleavage site; and wherein cleavage of the single-chain polypeptide by the exogenous protease converts the single-chain polypeptide from its single-chain polypeptide form into its di-chain form, thereby activating the single-chain polypeptide.
 39. A pharmaceutical composition comprising a carrier and a single-chain polypeptide activated according to claim
 38. 